Author response to “Lever effect and the optical illusion of safety in laparoscopic cholecystectomy”
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* Francis Sutherland

I thank Dr. McAlister for his letter commenting on our article. He brings up 2 important points that were not mentioned in the manuscript. The “lever effect” that the long laparoscopic instruments have on increasing the force at the instrument tip is certainly an underappreciated fact. Indeed, this may account for the difficulty many residents have in learning this procedure. Clearly, the harder one pulls on Hartman’s Pouch, the more the bile duct kinks, producing an increasingly convincing illusion.

Experienced surgeons develop many tricks that help them avoid mistakes, and these tricks are not mutually exclusive. We routinely use B-SAFE landmarks and the critical view of safety. Many tricks are subconscious and do not get passed on to our trainees. Looking for a route for any structure to return to liver is a “McAlister Wisdom” that we should impart to all our residents.

## Footnotes

*   **Competing interests:** None declared.

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