Which instrument is used to grasp the base of a hemorrhoid during a hemorrhoidectomy?

The Allis clamp is specifically designed to securely grasp and hold tissue, making it an ideal choice for procedures like a hemorrhoidectomy. Its serrated jaws provide a firm grip on the base of the hemorrhoid, allowing the surgeon to manipulate and excise the hemorrhoidal tissue effectively. The design of the Allis clamp ensures that it can maintain a strong hold on the tissue without causing excessive trauma, which is crucial during this delicate procedure.

In contrast, the other instruments listed have different purposes or designs that do not align with the requirements of grasping the base of a hemorrhoid. The Pennington forceps are more suited for holding tissue but do not provide the same grip as the Allis clamp. The Kocher clamp is primarily used for gripping and holding heavier tissue and is not ideal for the finer control needed in this context. The mosquito forceps are typically used for hemostasis or clamping small blood vessels and would not be appropriate for grasping the larger structures involved in a hemorrhoidectomy.