Suction-assisted lipoplasty: physics, optimization, and clinical verification

Although suction-assisted lipoplasty (SAL) has been clinically practiced for more than 25 years, comparatively little investigation into fundamental physics of the instrumentation used in the procedure has been conducted. Moreover, relatively little is known about the clinical impact or merit of the wide variety of instrumentation currently available.

In this study, we examined the physics related to the various components of instrumentation used in lipoplasty, and developed means to optimize performance based on quantified bench and clinical data.

The components used to construct a lipoplasty system (vacuum pump, suction tubing, suction canister, and suction cannula) were first evaluated using methods of bench experimentation. A selected set of components/parameters were then evaluated in a clinical setting, and the results were correlated to the bench data. The following design parameters were analyzed: for cannulas-shaft length, shaft internal diameter, port size/pattern, and venting; for tubing-length, internal diameter, and collapsibility; for canisters-volume, pull-down speed, gradation precision, and splash-related issues; and for vacuum pumps-vacuum level and flow rate.

Each of the system components can have a significant impact on the overall performance of the system. A simple calculation is presented that can be used to quantify the relative "resistance" and, therefore, speed of any selected cannula or tube. Port area is shown to be an important aspect of cannula design and clinical performance. Clinical data are shown to correlate reasonably with bench data, which imparts credibility to the bench data and provides a platform from which to extrapolate other bench data to the clinical setting.

With clinical objectives in mind, guidelines and recommendations are presented, based on the data we collected, to optimize a lipoplasty system with regard to choices of the vacuum pump, suction tubing, and canister. With the ideal system in place, the cannula becomes the only remaining variable. Cannula properties and performance were also studied and are discussed in detail.