80 Hemostasis for running locked versus running unlocked sutures

Abstract

The purpose of this study is to answer if running locked is more hemostatic than running unlocked sutures. We designed a high-fidelity physical simulation training model for suturing of blood vessels, specifically in the case of a uterine artery laceration. We created a physical simulation training model for suturing of blood vessels to mimic surgery in a laboratory experiment. A fountain submersible pump was fit to six-millimeter diameter latex tubing with a pressure gauge in line. The pressure gauge allowed us to set the pump to a specific pressure of 120 mmHg similar to systolic blood pressure at 250 milliliters per minutes of flow. Subsequently the surgeon made a two-centimeter incision in the tubing and collected the amount of fluid spill from the incision in a plastic enclosure. The tared weight of the fluid was collected from a plastic box enclosure for both locking and non-locking methods of suture closure to estimate blood loss. The method of incision closure was randomized by a random number generator. Each incision was closed with a standard number of three running sutures with an assistant providing the same traction. A metronome was used to keep time with each suture placement and we divided the fluid loss by the time to get a figure of estimated blood loss per second. Fifty trial simulations of running locked suture and another fifty were completed for running unlocked sutures to meet our power calculation. For all sutures, a 0-gauge United States Pharmacopeia polyglactin 910 suture was used. Knots were tied by a single investigator (SRR). Statistics were calculated using R 4.0.1 with exploratory.io. A total of 100 trial simulations were performed with half being closed with running locked and half closed with running unlocked. We found a statistical difference in the estimated blood loss per second between a running locked sutures (24.1 grams +/- 0.72) and running unlocked sutures (27.8 grams +/- 0.85, P < 0.01). Under laboratory conditions, running locked suture was more hemostatic than running unlocked suture. Using a running unlocked suture would allow for 500 milliliters more of estimated blood loss compared to running locked suture when closing a wound over two and a half minutes. Under laboratory conditions, running locked sutures allowed for less blood loss compared to running unlocked sutures.