Mesosigmoid

I designate this duplicature of peritoneum as Gruber's fold, because so far as I am aware, Gruber was the first to describe it. It controls to some extent the mesosigmoid and sustains it .from prolapse especially keeping it out of the pelvis.

This places the reflection under stretch and facilitates its division. (c) The reflection and underlying mesosigmoidal fascia have been retracted to the left and the mesosigmoid to the right.

The inferior mesenteric artery and vein are exposed by retracting the mesosigmoid to the left (by the assistant).