An Objective Comparison of Holding, Slippage, and Pull-Out Tensions for Eight Suspension Sutures in the Malar Fat Pads of Fresh-Frozen Human Cadavers

Abstract

In recent years, a number of designed suspension sutures have been rapidly introduced into clinical practice. This study compares the holding tension, slippage tension, and pull-out tension for each of 8 suspension suture systems randomly positioned in the midface soft tissue in 4 fresh-frozen cadaver heads. For each suture suspension system, a suture was positioned and set within the soft tissue of the cheek adjacent to the nasolabial line and attached to a tensiometer. A reference point was marked on the skin at the point where the suture first engaged the tissue. Holding tension was defined as the ounces of tension required to obtain a 5-mm superolateral displacement of the reference point. Slippage tension was determined by pulling further until the suture experienced its first slippage. Pull-out tension was defined as the ounces of tension required to pull the entire suture from its exit site. Photomicrographs of the fixation sites on the extracted sutures were examined and compared to their preinsertion state. Holding tension was statistically higher for the expanded polytetrafluoroethylene (ePTFE) knotted looped suture (W.L. Gore & Associates, Flagstaff, AZ) than for other systems. Slippage tension was greatest for the ePTFE suture; among other sutures, the tension profiles for the Silhouette (Kolster Methods, Inc., Corona, CA) and Woffles suture technique were higher than the others. In 3 of 5 cases, the ePTFE sutures demonstrated the highest pull-out tension, followed by the Silhouette and Woffles sutures. About 50% of barbs or cogs of polypropylene and polydioxanone sutures demonstrated bending, curling, or stripping away from the suture body after extraction. No morphologic flaws were found for suture knots, free-standing cones, or anchor pulleys. The various suture suspension systems currently available have differing efficacy and safety profiles. The results of this cadaver study clarify our understanding of the safety, benefits, and limitations of these systems. The higher ounces of tension for the ePTFE and Woffles sutures were to be expected, because these systems employ double suture strands that grasp a wider area than single-suture systems. Limitations of the study include the small number of samples, possible departures from clinical technique, and the inherent differences of the elastic and suture-holding properties between fresh-frozen cadaveric versus living tissue.