**1. Introduction**

The use of liposuction to contour the abdomen and trunk has been employed for almost 40 years [1]. Since its widespread adoption, there has been a continual evolution in technique and the addition of various complementary technologic adjuncts. Energy-based devices have been created to enhance the results of traditional liposuction. The currently available energy-based devices include ultrasound, laser, and radiofrequency. The primary goal of the majority of energy-based devices is to create skin and fibroseptal contraction to improve postoperative skin laxity. Power-assisted liposuction is often utilized in combination with these energy-based technologies to aid in surgeon comfort and efficiency. Several techniques and modalities may be combined to improve patient results.

### **1.1 SAFE (separation, aspiration, and fat equalization) liposuction**

We believe that incorporating the SAFE (Separation, Aspiration, and Fat Equalization) technique, as described by Simeon Wall, Jr., leads to superior liposuction results [2, 3]. As originally described, this technique involves three key steps: (1) separation of the fat using an exploded-tip or basket-tip cannula without suction, (2) aspiration of the fat, and (3) fat equalization again with an exploded-tip cannula off suction. Separation leads to mechanically emulsified fat while preserving vascular structures. Approximately 40% of the operative time is spent "separating" and the surgical endpoint is loss of resistance. Aspiration is then performed using less aggressive cannulas for 40% of the operative time. Finally, fat equalization is performed with a basket-tip cannula without suction. Any irregularities can

be smoothed out during this step and the fat is again emulsified resulting in a bed of "local" fat grafts. These "local" grafts prevent adherence of the dermis down to the underlying fascia. The surgical endpoint is a smooth rolling pinch test and a visibly smooth contour which translates to 20% of the total operative time.
