Indmedica - India's Premier Medical Portal - Cyber Lectures


Micro-Vascular Surgery

Dr. Ashok K. Gupta

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Can this procedure be repeated and if so how soon?

It may be possible to repeat the Suction Assisted lipolysis for a touch up job in previously aspirated area, but technically it is more difficult then otherwise. However, it is recommended to defer the subsequent stages of Suction Assisted lipolysis for at least three weeks, when done in different zones and for three months in the same area.

How much weight loss can be effected by SAL?

By and large, Suction Assisted lipolysis is aimed at reduction in girth and extra deposits of fat. The actual weight loss immediately Post-SAL may not be so significant, however, the contouring is excellent. Body itself releases some sort of inhibitory substance, which does not allow re-deposition of fat in the lipolysed area.

Suction Assisted lipolysis has been termed as the most significant surgical development of the “Decade in Aesthetic Surgery” .

What is an Auto-Fat injection method or procedure?

It is one of the ancillary procedure, which has become popular for smaller defects. A relatively small quantity of fine fat globules are aspirated, using a special syringe and thereafter, it is injected in areas like face, cheek, small depression on extremities etc. It must warned at this stage that the fat transplanted may not remain in the injected area and may get absorbed with more fibrosis. Results achieved may be temporary and may require a number of re- injections.

What is superficial Lipo-suction?

Superficial Suction Assisted lipolysis is relatively new in clinical practice. The amount of depth of subcutaneous fat left underneath the skin is kept to minimum in superficial Suction Assisted lipolysis . It is a extremely useful method for countering of the facial region, gynecomastia, thin abdomen, banana fold in the gluteal region, calf and ankles etc. Fine size Canula 1 – 2 mm. with a hand-operating syringe is used. Suction performed without the suction machine has extremely gratifying results, but without the complications of waves and daves. It can be combined with an ancillary procedure like face-lift.

Ultra Sound Assisted lipolysis (UAL) has been introduced recently, promising a voluminous body contouring without significant blood loss and absence of any postoperative bruising.

Ultra Sound Assisted lipolysis (UAL)

A revolutionary body-contouring technique based on the use of Ultrasonic Energy allows the selective destruction of only Adipose Tissue. Cavitation caused by the Ultrasonic Energy acts primarily on the liquid within the fat cells and if properly used, has no effect on the vascular, nervous, or connective tissue components. Ultrasonic-assisted Lipoplasty (UAL) evolved from Closed Liposuction developed in the late 1970s by Schrudde, Fisher, and above all Illouz? who were prominent in advancing the technique of closed Liposuction through small incisions.

Closed Liposuction has been refined by many surgeons and is the most frequently performed surgical procedure. Ultrasonic Lipo-sculpture, in which fat is liquefied with the use of Ultrasonic Energy and then evacuated from the subcutaneous space, offers the advantages of reduced blood loss, more specific treatment and removal of excess fat, and the possibility of massive reduction of fat (up to 12 L in the same surgical session without major hemoglobin loss (less than 4 g).

Ultrasound waves are produced by transforming normal electric energy into high-frequency energy-over 16 kHz (16,000 cps), which is too high to be perceived by the human ear. This energy, which is transmitted to one or more piezoelectric quartz crystal or ceramic transducers, is transformed into mechanical vibrations that are amplified and transmitted. Ultrasound has been used in industry for plastic material welding and metal cleaning and in medicine to obtain images for diagnostic purposes. Nevertheless, none of these applications make use of ultrasound’s physicochemical effects.

Ultrasonic effects on fluids are mainly caused by the complex physical processes produced, i.e., by implosion of Micro-cavities containing gas and vapors. Ultrasonic waves, like all sound waves, have expansion and compression cycles. Compression cycles exert positive pressure on fluid molecules, whereas expansion cycles exert negative pressure. A sound wave of adequate intensity can generate Micro-cavities during its expansion cycle. If Micro-cavities are overexposed to Ultrasonic Energy, they are affected by alternate expansion and compression cycles of the sound wave. This makes the bubbles expand and contract continuously at a frequency corresponding to the ultrasonic wave. A dynamic balance between the gas inside the bubble and the surrounding structures is reached. In some cases, ultrasonic waves feed a bubble whose dimensions continuously change; in other cases, the average size of the bubble tends to increase.

The increase in size of a cavity also depends on the intensity of the sound wave. High-intensity ultrasound can cause a Micro-cavity to expand so quickly during the negative-pressure cycle (expansion) that it can no longer contract during the positive-pressure cycle (compression). Therefore in this process, Micro-cavities can increase in size and reach the critical phase in a very short time. However, with low-intensity ultrasound, the size of the Micro-cavity changes according to expansion and compression cycles. The surface of a Micro-cavity produced by low-intensity ultrasound is slightly bigger during expansion cycles than during compression cycles. Since the amount of gas diffusing into and out of the Micro-cavity depends on its surface, outward diffusion during expansion cycles slightly exceeds that during compression cycles; therefore at every wave cycle the Micro-cavity expands a little more than it contracts. Many cycles are needed to slowly increase the size of a Micro-cavity.

With high-intensity and low-intensity ultrasound, the Micro-cavities do eventually reach a critical size enabling them to absorb energy efficiently from the ultrasound as a function of the frequency of the ultrasonic waves. For example, at 20 kHz (the frequency used to perform Ultrasonic Lipo-sculpturing) the critical size of a Micro-cavity has a diameter of about 170 fEm. At this point the size of a Micro-cavity increases logarithmically during a single cycle of the sound wave, but the Micro-cavity cannot absorb further energy from subsequent sound waves. Because of the lack of further energy, a Micro-cavity cannot survive and succumbs to the surrounding pressure by imploding.

Clinical application of ultrasound energy requires a device that works in the low range of ultrasound (20 kHz). The frequency of the ceramic piezoelectric transducer we use functions at just under 20 kHz (19,800 cps). We employ an ultrasonic generator that can produce 99 W of total power; for standard body remodeling, we usually operate the machine at a setting level between 60% and 70% of maximum power. The amplitude is automatically set to a level of 140/150fE by the ultrasonic machine, which adapts the setting to the different types of titanium probes and the consistency of the tissues being treated. The energy delivered at these levels can cavitate and destroy lipocytes while sparing the important vascular, neural, and other connective tissues. The liquefied fat must be removed from the treated site mechanically with low-level aspiration (0.2 to 0.4 bar), and then all the denser tissues left in place are manually remodeled and homogeneously spread by external pressure on the treated area immediately after completion of the ultrasonic treatment, using a special instrument developed for this purpose.

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