Isobutyl cyanoacrylate as a soft tissue adhesive. An in vitro study in the rabbit Achilles tendon

Cyanoacrylates (CAs) are biodegradable, bacteriostatic, and hemostatic adhesives. CAs have been used in medical applications, but with adverse effects, including excessive inflammatory reaction and neural toxicity. Isobutyl CA (ICA) appears more biocompatible, with a long half-life that may be ideal for a soft tissue adhesive. The rabbit Achilles tendon was chosen to test (ICA), and a special muscle-freezing clamp to test this model was designed. The tendons were sharply cut 2 cm proximal to their insertion and repaired in four groups. They were tested to failure on an Instron machine. The breaking strength of the repairs was then noted. Also, the breaking strength of several suture materials was tested. Four Achilles tendon repair groups were evaluated: ICA alone 9.03 newtons (NTS); 4-0 silk Kessler stitch, mean 12.9 NTS; Kessler stitch plus three simple stitches, mean 23.0 NTS; and a combination of (a) and (c)--i.e., suture and adhesive, mean 40.2 NTS. The intact Achilles tendon was tested with an average breaking strength of 317 NTS. The muscle-freezing clamp facilitated reasonable testing of this tendon repair. ICA alone exhibits reasonable strength in vitro and in combination with suture provides a stronger initial repair than either suture or adhesive alone.