Biomechanical evaluation of finger trap suture variants for securing catheters

To biomechanically evaluate various finger trap patterns and suture materials for securing 5F polyvinylchloride and polypropylene catheters.

In vitro prospective study.

132 finger trap constructs.

Each group of constructs comprised 6 to 10 replicates each of 3 finger trap patterns tied with 2-0 glycolide-lactide copolymer (GLC), braided nylon, and monofilament polypropylene suture on 5F polypropylene and polyvinylchloride catheters. The 3 finger trap variants were of similar lengths but differed in the number of surgeon's throws included in the pattern. Constructs were tested with a universal materials testing machine to the point of failure or a maximum of 100 mm of distraction. Force and distraction data were evaluated for significance with a competing risks model.

There was no difference in performance (as measured by the proportion of test failures, median distraction distance, or median force at failure or end of testing) attributable to the finger trap pattern variants. Sixteen of 66 constructs with polyvinylchloride catheter material failed at ≤ 100 mm distraction, whereas all polypropylene constructs failed during testing. For polypropylene catheters, braided nylon or GLC suture withstood greater distraction distance and force, respectively. For polyvinylchloride catheters, differences among suture types were nonsignificant.

Data suggested that, for the material combinations evaluated, a finger trap suture pattern with fewer knots may provide catheter security similar to that for patterns tied with a more traditional pattern. These results should not be extrapolated to catheters of different diameters or materials, patterns tied with different suture sizes, or clinical performance in vivo without further testing.