Another look at aesthetic body health.

Ultrasound-assisted liposuction (UAL).

From the tumescent method to High Definition with the VASER Lipo.


Plastic, reconstructive and aesthetic surgeon.
Clinique Esthétique Paris Étoile. 12 rue Beaujon 75008 Paris


In the age of social networking and the cult of the "perfect" body, surgeons have to deal with increasingly demanding requirements from connected patients who are kept abreast of the latest developments in cosmetic surgery.
Ultrasound-assisted liposuction (UAL) got off to a rocky start, losing popularity in the late 1990s.
We had to wait until the early 2000s and the third generation (VASER). ultrasonic technologies, and the popularization of high-definition methods by Colombian surgeon Alfredo Hoyos to give this technology a new lease on life and gain the support of plastic surgeons worldwide.
There is still a long way to go in France, where to date only a handful of surgeons have adopted this technique, despite numerous studies attesting to the safety, efficacy and numerous s advantages of using ultrasound compared to a traditional method, including in surgeries with a reputation for difficulty, such as the surgical treatment of lipoedema.
Fat extraction techniques for the modification of the shape and contours of the silhouette have undergone major improvements in recent years.
The initially large and blunt liposuction cannulas have been replaced by thinner and softer cannulas.
Tumescent techniques (TAL, Tumescent Assisted Liposuction), wet and superwet have replaced the more aggressive dry methods.
PAL-type devices (Power Assisted Liposuction) that facilitate fat extraction and improve surgeon comfort have appeared, reducing complications and improving skin retraction.
Patients' expectations began to rise with the emergence of social networks and the importance attached to body image in a multi-exposed world.
Aesthetic surgeons wishing to respond to a new demand have proposed different models of treatment, notably with the appearance of high-definition liposuction, including Colombian surgeon Alfredo Hoyos is the instigator.
The methods used by Hoyos systematically integrate a ultrasonic liposuction system (UAL, Ultrasound Assisted Liposuction), called VASER Lipo® and achieve spectacular results in "body contouring.

History of VASER technology

The use of ultrasound for surgical procedures is not new.
In 1967, Kelman introduced phacoemulsification for cataract treatment after discovering his dentist's ultrasonic scaling machine [1].
Since then, ultrasound has been used extensively in neurosurgery for the targeted destruction of tumors, and in general surgery for sectioning and coagulation in laparoscopic surgery [14].
Scuderi and Zocchi were the first to use ultrasonic energy for selective emulsification and fat removal in the body contouring in the late 1980s and early 1990s [2, 3, 16].
The first generation of ultrasonic machines was developed in Italy (SMEI) and involved the use of 4-6 mm diameter probes, emulsifying grease at a frequency of 20 kHz.
In the mid-1990s, two other companies proposed two second-generation systems delivering ultrasound at a higher frequency and combining emulsification and concomitant suction (fig. 1).

Figure 1. comparison between the first (left) and third generation (2 right) ultrasound probes (after A. Hoyos. High Definition Body Sculpting. Springer 2014).

Because of the loss of protective infiltration due to the combination of ultrasound emission and suction, numerous complications have arisen, bringing this method into disrepute and causing its popularity to decline sharply [4-6].
In 2001, another company introduced a third-generation machine designed to reduce the energy delivered to the tissues, thus increasing operating safety while maintaining efficiency: the VASER. Smaller diameter probes (2.2 to 4.5 mm) were introduced, and their design was completely rethought to emulsify grease efficiently at a frequency of 36 kHz.
The versatility of this new system means that ultrasound treatment can be applied to almost any area of the body [7].
The VASER is currently the gold standard for carrying out body contouring in high definition. The resonance effect used by the VASER explains why it differs from older technologies, particularly in terms of fewer complications and better results. This resonance concept is based on two principles:
- the first is the frequency of the Vaser (36 kHz), which is much closer to the fat's resonance frequency, allowing emulsification with less energy delivered;
- the second is related to the size of the cells, the adipocytes being ten times bigger than the surrounding cells (nerve cells, endothelial cells and connective tissue), they are more sensitive than their neighbors to the ultrasonic energy.

Principles of ultrasound-assisted liposuction and VASER

Vibratory amplification of sonic energy through resonance (VASER) is the third generation of LAU machines using ultrasonic energy to emulsify fat and extract it from the body [8].
This technology emulsifies fat while preserving the surrounding noble tissues (vessels, nerves, etc.). It is used in three stages: infiltration of the treated tissues using a tumescent technique, emulsification of the adipose tissue using cannulas delivering ultrasound and aspiration of the adipose emulsion.
The system VASER consists of an electrical generator and an ultrasound handpiece (fig. 2).

Figure 2: VASER L amplifier consoleipo, handpiece and probe.

Figure 3: Piezoelectric transducer

Inside the handpiece, electrical energy is converted into mechanical energy in the form of vibrations through a piezoelectric transducer (fig. 3).
The vibrations generated are then conducted through the handpiece to the titanium probe, which is manufactured to vibrate at a frequency of 36 kHz in the case of the VASER. At this frequency, the probe vibrates longitudinally with the handpiece with maximum amplitude at the tip of the cannula, where the energy is concentrated. Although the displacement of the probe is in the micron range, this is powerful enough to act on the surrounding tissue. By increasing the generator's power, the cannula's movements become more ample and efficiency increases.
The interaction between the titanium probe and adipose tissue leads to fat emulsification and can be divided into three mechanisms: cavitation effect, mechanical effect and thermal effect [8, 9,12]. The cavitation effect occurs when microscopic air bubbles in the infiltration fluid expand as a result of compression (fig. 4).

Figure 4: Illustration of the cavitation effect. VASER® probes vibrate at ultrasonic frequencies, creating compression and rarefaction forces around the tip of the cannula. The fine air bubbles grow and implode, releasing the energy that causes the adipocyte lobules' architecture to collapse into a fluid fat emulsion. (Based on A. Hoyos High Definition Body Sculpting. Springer 2014).

These air bubbles grow until they implode, releasing energy that separates the adipocytes from their supports (septa and fibrous tissue) within the lobule.
This cavitation effect occurs in the immediate vicinity of the cannula tip, an area of no more than a few cubic millimeters.
This is important when planning the cannula's passage, as all the tissues to be treated must accommodate the cannula's passage for optimum results.
The mechanical effect occurs at the tip of the cannula, where the vibrating metal surface comes into contact with the adipocytes. Keeping the metal cannula moving within the tissue prevents overheating due to the high frequency of the vibrations. The thermal effect here is undesirable, and only contributes to the occurrence of seromas or burns.
The main advantages of VASER® are its reliability, efficacy and safety, enabling it to be used on almost the entire body, as well as on superficial planes [7].
The Vaser® is safer than earlier generations of ultrasonic systems, for a number of reasons.
The first is that ultrasound cannulas are non-aspirating, ensuring maximum tissue protection from the previously infiltrated liquid throughout the entire procedure.
It goes without saying that ultrasonic energy should only be used in a moist environment for optimum tissue protection.
The second reason is that the cannulas of the VASER® are significantly thinner than first- and second-generation cannulas (fig. 5).
Given that the amount of energy delivered to tissues is relatively proportional to the surface area of the cannula diameter, the use of smaller diameter cannulas reduces tissue exposure to the energy released by the system. Finally, the third reason is the selectivity of the ultrasonic energy delivered to adipose tissue, so that potential damage to surrounding tissue (lymphatics, nerves, vessels) remains limited.
The many advantages of using VASER® are clinically characterized postoperatively by easier recovery for patients, with less edema, less bruising and less pain. In addition, the use of VASER® in body contouring surgery has shown a reduction in blood loss and an increase in skin retraction compared with a conventional liposuction technique [10].
These benefits are particularly important in high-definition procedures, given the large surface areas treated in a single procedure and the need to maximize skin retraction to reveal underlying muscle structures.

Figure 5. VASER® ultrasound probes from left to right: 1 groove (3.7 mm diameter),  2 grooves, 3 grooves, 3 grooves (2.9 mm diameter), 5 grooves.

Vaser system technology and instrumentation®

Composed of a generator console, a handpiece, a trigger pedal and various probes and accessories, the VASER system® offers a concentrate of reliable, ergonomic and easy-to-use technology (fig. 6 and 7).

Figure 6. Translator handpiece.

Figure 6. Protective cap for probe base.

Figure 7. Wired and wireless activation pedal.                              

Figure 7. Complete VASER® system. 

The amplitude of the delivered energy can be adjusted directly on the console in increments of 10 % from 0 to 100 % [13].
Titanium probes screw directly onto the handpiece responsible for converting electrical energy into ultrasonic energy, and feature a plastic safety cap.
Different probes are available with diameters of 2.2, 2.9, 3.7 and 4.5 mm. These probes are grooved at the tip, and the number of grooves influences the amount of energy and the direction in which this energy is delivered.
The choice of probes (length, diameter, number of grooves) will depend on several parameters: the body area to be treated, the fibrous nature of the fat to be extracted, whether liposuction is combined with a plastic surgery procedure, the surgeon's experience, the technical procedure performed...
The VASER system difference® with its predecessors also lies in the possibility for the user to choose the mode of energy delivery, i.e. the VASER® mode (discontinuous mode) and continuous mode.
For high-definition surface work, the VASER® mode will be preferred.

Technical basics for Vaser use®

The use of adrenalinized hypo-osmolar infiltration solution is recommended, with the ratio of infiltrated volume to total volume of fat removed ranging from 1.5:1 to 2:1.
It is important to infiltrate all areas to be treated carefully, even slightly beyond the marked areas.
It is recommended to allow 8 to 10 minutes to elapse between the end of the infiltration time and the start of VASER use.® to achieve optimal vasoconstriction.
Skin protection supports are then inserted through an incision of a few millimeters and screwed or sutured directly to the skin, providing effective protection for the edges of the skin incision (fig. 8 and 9).
After adjusting and testing the machine, the surgeon then introduces the chosen probe through the hole in the holder. The probe must be easy to insert and penetrate the tissue easily. If this is not the case, a more suitable probe should be selected.
The probe must be kept moving and moved smoothly, without snagging tissue or exerting excessive pressure. The probe must not stagnate in one place when triggered.
Various criteria not detailed here can inform the surgeon about the efficacy of Vaser treatment, such as the reduction in resistance to cannula passage.
Once treatment with VASER® performed, the surgeon completes the procedure by liposuction of the emulsified areas using the technique of his choice.

Advantages of using VASER®

Various studies have been published over the past twenty years on the use of ultrasound in cosmetic surgical procedures. A multicenter, single-blind study published in the " PRS " in 2012 [10] demonstrated the safe use of the VASER®. Surgeons who have been using this technology for some twenty years in various countries around the world have noted the major advantages provided by the system, particularly in fibrous lumbar and flank areas, but also during secondary liposuction [11].
Although the use of VASER seems to increase operating time compared to conventional liposuction, due to the time required to emulsify the fat before aspiration, this time is recovered during extraction, which is facilitated by the fragmentation of fibrous fatty tissue. This technology offers numerous advantages [11].
The finesse of the ultrasound probes and the customization of settings for each body zone enable gentle treatment of superficial tissues without causing irregularities. Discontinuous mode (VASER® mode) reduces the energy delivered to tissues, enabling subdermal use without causing damage to surrounding structures. Selective emulsification of fat and sparing of surrounding tissues enables fat extraction with reduced blood loss, less oedema and bruising, and faster recovery.
Extracted fat can also be used for all adipose autograft procedures, with adipocytes collected using VASER® have a good survival rate[15].
Disadvantages of using VASER®
Using VASER technology® requires an expensive piece of equipment that requires careful thought on the part of the surgeon wishing to acquire it. Indeed, an investment of this order for occasional liposculpture practice does not, in our view, seem appropriate.
Beyond the financial aspect, surgeons wishing to equip themselves with the VASER® should be made aware of the personal investment of time and energy required to get to grips with the device in the safest possible way.
Training by an expert familiar with the technique is essential, as the VASER learning curve® being long and non-linear.
Despite the reduction in ultrasonic energy transmitted to tissues, making this third generation of devices the safest to date, the risk of superficial burns is not nil, and teaching how to avoid them adds to an already long learning curve[17].

Our experience with the Vaser®

We use the VASER® since the beginning of 2020, and to date have treated several hundred patients with this technology. Our experience with this procedure has led us to treat all areas of the body (neck, arms, chest, abdomen, thighs, calves, back, buttocks and knees) eligible for this innovative treatment. We found that the system was relatively easy to use, but required a great deal of training and a relatively long learning curve. The main advantages of this technique include accelerated recovery in treated patients, with reduced clinical stigmata of liposuction compared with conventional methods, and easier fat "sculpting".
The surgeon's comfort during the liposuction procedure is greatly enhanced by the fragmentation of the fat lobules, and this is particularly appreciable during secondary liposuction.
The figure 10 shows some examples of body areas treated with Vaser technology®.

Lipoedema treatment with VASER technology®

Lipoedema is a chronic, progressive and disabling disease of the subcutaneous fat of the lower limbs, affecting women almost exclusively.
It is characterized by a bilateral increase in the circumference of the legs, with painful sensations and ecchymosis following minor trauma.
The disease is often referred to as painful lipodystrophy.
Described by Allen and Hines in 1940 This pathology remains largely under-diagnosed and relatively unknown to the medical profession, yet it affects up to 10% of the adult Caucasian female population [18].
Lipoedema is also frequently referred to as "two-body syndrome". in reference to the ease of diagnosing the disease by comparing proportions between the trunk and lower limbs.
The circumference of the legs is abnormally enlarged, and the accumulation of fatty tissue stops clearly at the ankles.
Unlike lymphedema, lipoedema spares the extremities, feet and hands [19].
Bruises easily appear in the affected areas after minor trauma.
The consequences of lipoedema are numerous, including reduced mobility, painful symptoms, difficulty dressing, reduced quality of life...
The treatment of lipoedema by liposuction was first described by Schmeller and Meier-Vollrath [20].
The method rapidly became the gold standard in the management of lipoedema [21].
It is indicated for patients with symptoms resistant to conservative treatment, or in the event of worsening of the disease (volume of excess fat) and/or exacerbation of symptoms.
The objectives are multiple: to reduce pain, bruising, oedema and limb circumference. This will have a positive impact on patients' mobility and quality of life. Fatty deposits are virtually eliminated, and symptoms disappear almost completely. Studies report an improvement in pain, oedema, bruising and mobility limitations, as well as better physical appearance and enhanced quality of life for over 90% of patients.
VASER liposuction® is used worldwide for the surgical treatment of lipoedema, since it limits intraoperative blood loss, improves the "scalloped" skin appearance characteristic of lipoedema and facilitates limb sculpting (fig.11) to restore the natural curves of the legs so desired by sufferers.


In the age of social networking and the widespread cult of the "perfect" body, aesthetic surgeons the world over are faced with the growing expectations of their patients, who benefit from an open window on the technical advances of our specialty on the screen of their smartphone.
These technological developments may well call for a rethink of our traditional methods, with a view to gradually integrating new models of care into our practices, as well as new technologies that could improve patient comfort and outcomes.


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Aesthetic health based on scientific evidence

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