Effect of fluid media on the mechanical properties of continuous pattern-ending surgeon’s, square, and Aberdeen knots in vitro.

The study researches the effect of certain fluids, usually found during equine abdominal surgery, on the knot holding capacity (KHC) of specific surgical knots when tied with different types of sutures. It found that in most cases, exposure to these fluids either did not change the KHC or actually improved it.

Methods

• The research was conducted as an in vitro mechanical study, using pre-knotted strands of two different types of suture material.
• These strands were then exposed to one of four different fluids commonly present during equine abdominal surgery: balanced electrolyte solution, 1% sodium carboxymethylcellulose, equine serum, or equine fat. Control strands were not exposed to any fluid.
• The research analysed three different types of surgical knot: the square knot, the surgeon’s knot, and the Aberdeen knot. Each knot was tied in up to four different combinations of throws, essentially the loops that make up the knot.

Results

• The KHC of surgeon’s knots tied with 3-polyglactin 910 suture material were found to have significantly higher KHC when they had been exposed to the study’s fluids and had 5 or 6 throws.
• Square knots tied with 3-polyglactin 910 were found to have a significantly higher KHC when exposed to the study’s fluids and had 5 throws.
• Aberdeen knots tied with either of the study’s suture materials had a significantly higher KHC after fluid exposure, regardless of the number of throws.
• Aberdeen knots showed superior KHC overall, despite requiring less suture material than the other knot types.

Conclusions

• The study’s results indicate that exposure to surgical fluids can either have no effect on the KHC of surgical knots, or improve it significantly.
• Based on the results, when taking into account both KHC and knot volume, the researchers recommend the use of Aberdeen knots, specifically those tied with three throws and one turn of 3-polyglactin 910 suture material that’s been exposed to fluid, for ending a continuous suture pattern in equine abdominal surgery.