Evaluating the Burst Pressure of Simulated Bowel Anastomosis Constructed Using the Reverse Half-Hitch Alternating Post Knots

Square knots are the gold standard for hand-tied surgical knots; however, they are difficult to reproduce in deep body cavities and can inadvertently result in slipped knots. The investigators have shown in previous work that the reversing half-hitch alternating post (RHAP) surgical knot is a non-inferior alternative to the square surgical knot based on its tensile strength and performance in limited working spaces. Prior to introducing RHAP knot in routine surgical practice, it is important to objectively demonstrate similar physical characteristics of anastomosis created using RHAP and standard square knots. This study aims to compare the burst pressure of cadaveric porcine small bowel anastomosis constructed using RHAP and standard square knots on a flat surface and in a simulated deep body cavity.

The investigators are conducting a prospective randomized controlled study of novice medical students allocated to proficiency-based training in RHAP and square surgical knots. Knot tying proficiency will be assessed using a knot-tying checklist. Number of repetitions and time required to achieve proficiency will be tracked for each group. Once proficiency has been achieved by participants in RHAP and square knots group, each participant will perform two-hand sewn small bowel anastomosis using cadaveric porcine small bowel. One anastomosis will be performed on a flat surface and the other will be formed in a simulated deep body cavity. Burst pressure of the anastomoses will be tested using a column of water, and results will be compared between groups. Simple descriptive statistics will be performed for both groups. Between group comparisons of knot-tying proficiency and burst pressure will be performed using t-test. Learning curves within each group will be analyzed using paired 1-way ANOVA. SPSS Statistics (v. 21, IBM, New York, USA) will be used for all statistical analysis, with significance set to p<0.05.

The investigators hypothesize that burst pressure of cadaveric porcine small bowel anastomosis will be equivalent for anastomosis constructed using RHAP and standard square knots.

The results of this study will provide further validity evidence in support of RHAP as suitable alternative to the square surgical knots.