Figure 8.

Treatment of the pituitary tumor via TSS using a high definition arthroscope. As Mamelak AN reported in 2014,³⁰ magnifying and illuminating the operative field helps surgeons perform TSS. A high definition arthroscope with a xenon fiber optic light is also useful for TSS. An eleven-year-old, castrated Toy Poodle was referred with complaints of polyuria, polydipsia, and alopecia (A). Preoperative MR T2-weighted images revealed an enlarged pituitary tumor (B; sagittal, C; transverse). PBR was 0.73, and MRI-grading was III-A. TSS was performed using a high definition arthroscope. Series of figures (D) to (G) show the process of TSS. (D) The opening in the sphenoid bone. The ventral surface of the pituitary mass was confirmed. (E): Incision of the dura in a cruciate pattern was made. (F): Tumors were removed using a grasper and suction through the opening of the sphenoidal bone. (G): After the tumor was almost completely removed, the arthroscope was introduced into the third ventricle, which was enlarged by the growth of the tumor. The ventral side of the interthalamic adhesion was seen (＊). Immediate postoperative MR T2-weighted images revealed an enlarged and air-filled space in the third ventricle, due to the removal of the tumor (h; sagittal, i; transverse). Figure (J) represents the gross appearance of this case at 6 months after TSS. The systemic alopecia observed prior TSS gradually remitted.