title: Enhancing lipoaspirate efficiency by altering liposuction cannula design.
abstract: BACKGROUND
  Interplay between the components of a lipoplasty system (suction pump, suction tubing, collection canister, and cannula) determines liposuction efficiency. However, in clinical practice, none of the components are more important than the cannula. Cannula design including port design, port placement, and shaft characteristics is the single most influential contributor to flow resistance and dramatically effects speed of aspiration and final contour. Many variations on port design and placement are available, yet functional enhancements to the cannula shaft have largely been ignored. We have engineered a set of novel cannulas addressing vital elements of cannula design in the effort to enhance aspiration efficiency and efficacy.
  
  
  METHODS
  Two novel cannula designs (dual- and multiport, in-line configuration), created using a unique proprietary manufacturing process, were evaluated against a popular industry standard design (tri-port, Mercedes configuration) to assess aspiration efficiency. Cannulas with shaft diameters of 3, 4, and 5 mm were attached to a standardized lipoplasty system and evaluated in real time for their ability to aspirate a viscous applesauce medium over a 5-minute time course. For each cannula, we calculated (1) the cross-sectional area of the cannula shaft, (2) single and total port area, (3) port-to-shaft ratio, and (4) theoretical resistance.
  
  
  RESULTS
  The relationship between the cannula shaft and cannula port(s) directly influenced flow dynamics. Comparing medium uptake time, aspiration efficiency and the aspiration curves demonstrated a significant improvement of the 2 novel cannulas over the standard cannula in the 5- and 4-mm designations. In the 3-mm group, a difference in uptake time remained. However, a significant difference in aspiration efficiency was only seen between the dual-port novel cannula and tri-port Mercedes standard cannula. Further, differences in the aspiration curves between all 3-mm cannulas approached but did not reach significance.
  
  
  CONCLUSIONS
  We have developed 2 novel cannulas that maximize port features and seek to minimize the internal shaft resistance. Both designs demonstrate enhanced aspiration and uptake compared with an industry standard design.
authors.affiliation: Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Beck
authors.affiliation: Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Davis
authors.affiliation: Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Rod J
authors.initials: RJ
authors.lastname: Rohrich