Changes in knot-holding capacity of sliding knots in vivo and tissue reaction

Objectives: To evaluate and compare the in vivo strength, knot efficiency, and knot security of 4 types of sliding knots, and to assess tissue reaction to study the effect of knot configuration, knot volume, and suture size. Design: Randomized trial. Setting: Experimental Medical Research Institute, Istanbul, Turkey. Subjects: Wistar rats. Intervention: To assess the tissue reaction, a midline laparotomy incision was made in 112 rats and sutured with various interrupted knots in silk and nylon sutures of 2/0 and 4/0 (United States Pharmacopeia) sizes. Suture loops were implanted in subcutaneous pouches in the rat abdomen. Sutures were all extracted at days 4, 7, 11, and 20 to determine their knot-holding capacity. Main Outcome Measures: Knot efficiency and percentage decrease in knot-holding capacity were examined. Knot, tissue reaction, and inflammatory sheath volumes were measured. Results: The 4/0 knots lost more strength than the 2/0 knots. The alternating knots with different patterns were more efficient and secure than the simple alternating ones. The alternating parallel knot was found to be unreliable. The tissue response to all the knots, except 2/0 nylon, was similar. The inflammatory sheath volume var led depending on the knot volume, suture size, and knot configuration. Conclusion: The use of alternating sliding knots with different patterns is recommended to replace simple alternating sliding knots.