WHICH KNOTS ARE RECOMMENDED IN LAPAROSCOPIC SURGERY AND HOW TO AVOID INSECURE KNOTS

ABSTRACT Study Objective To investigate why security of identical knot sequences is variable and how to avoid occasionally insecure knots. Design A factorial design was used to assess factors affecting the security of half knot (H) and half hitch (S) knot combinations. The effect of tying forces and the risk factors to transform H knots into S knots were investigated. The risk factors evaluated were starting with an H1 or H2 instead of an H3 knot, inexperience, short sutures, and mono-manual knot tying. Security of transformed knots, S2S1 and S2S2 knots and their recuperation with 2 additional half hitches, SSb or SbSb was evaluated. Setting Training centre for laparoscopic suturing Patients Not applicable Interventions Security of knots was evaluated in vitro. Measurements The forces which caused knot combinations to open before breaking of the suture, were used to calculate the risk of opening with low forces. Main Results Tying more strongly increased the security of half knots (H2H1sH1s) (P Conclusion To reduce the risk of accidentally transforming a first H into an S knot, it is recommended to start with an H3, to tie with force, to avoid short sutures and to use bimanual suturing. This permits the recommendation to use preferentially H3H2 knots or 5 Half Hitches (SSSbSbSb). In doubt half knot combinations should be secured with at least 2 blocking half hitches.