Ex vivo comparison of the giant and transfixing knot in equine open and closed castration

"The Gordian knot of it he will unloose": Lessons learned from studies of half-hitch surgical knots and implications for practicing surgeons: A systematic review

BACKGROUND

Insecure surgical knots can cause surgical complications ranging from wound dehiscence to massive exsanguination and death. Most surgeons tie half-hitch knots, of which some configurations are prone to slippage. We aim to characterize the securities of different half-hitch knot configurations.

METHODS

A literature search was conducted using PubMed and Embase for studies in which comparisons of knot security were made between different half-hitch knot configurations. Two reviewers screened and selected articles.

RESULTS

From 2,204 abstracts identified, 14 were selected for inclusion. In all 8 of the studies in which there was a direct comparison between knots tied with opposite throws on the same post, which are tied when greater tension is applied to the same strand end, and knots tied with any throws on alternating posts which are tied when the strand on which greater tension is applied switches between the strand ends, there was at least one comparison of configurations in which any throws on alternating posts knots were more secure than opposite throws on the same post knots. There was also less variability in the securities of any throws on alternating posts knots than opposite throws on the same post knots. Knots tied with identical throws on the same post were less secure than opposite throws on the same post and any throws on alternating posts.

CONCLUSIONS

The securities of half-hitch knots exist on a spectrum. any throws on alternating posts knots were consistently the most secure independent of whether throws were opposite or identical, and identical throws on the same post knots were less secure than opposite throws on the same post and any throws on alternating posts. Surgeons should consider any throws on alternating posts knots as opposed to the more commonly utilized opposite throws on the same post knots.

Evaluation of three ligatures in simulated equine open castration

OBJECTIVE

To compare three surgical knots for preventing leakage from the vascular bundle during ligation in simulated equine open castrations.

STUDY DESIGN

Randomized, case-control, in vitro study.

SAMPLE POPULATION

Testes (N = 60) collected from 30 horses.

METHODS

Testes were collected from 30 horses and randomly assigned to one of three groups: group G (friction, giant knot), group T (modified transfixing knot), or group S (sliding, strangle knot; n = 20/group). The assigned knot was used to ligate the vascular bundle during open castration. The length of suture material used and the leak pressure of the testicular artery were measured and compared between groups.

RESULTS

Strangle knots consistently leaked at higher pressures (median, 735.5 mm Hg; interquartile range [IQR], 735.5-735.5) compared with giant (median, 441.3 mm Hg; IQR, 367.8-643.6) and transfixing (median, 419.2 mm Hg; IQR, 323.6-643.6; P < .0001) knots. Both the strangle (median, 5 cm; IQR, 4.5-5.5) and giant (median, 6 cm; IQR, 5.35-6.075) knots required less suture material compared with the transfixing (median, 9.2 cm; IQR, 8.425-10.38; P < .0001) knot.

CONCLUSION

The three surgical knots tested withstood pressure well above physiological levels in simulated open castrations. The strangle knot withstood higher pressure and required similar (giant) or less (transfixing) suture material than the other two knots.

CLINICAL SIGNIFICANCE

This study provides evidence to support the use of a strangle knot to ligate the vascular bundle during simulated open castrations in horses.