A medical needle set for visualized tissue ablation within a subject's body includes a cannula and components configured for inclusion in the cannula, including a trocar for occlusion of the cannula lumen during needle placement, and a visualizing ablation probe used for simultaneous endoscopic viewing and ablation of tissue sites with a laser beam. The cannula can include a tissue-gripping surface for stabilization of the needle set on the target tissue. A surgical system for tissue ablation includes a visualizing ablation needle set operably connected to an endoscope and a laser. A surgical procedure using this system permits simultaneous visualization and ablation of tissues, including those of the facet joints of the spine.