There is disclosed herein a biopsy needle assembly configured to collect histological samples via a surgical visualization device, the assembly comprising an elongate notched needle cannula including a distal notch open to a longitudinal needle cannula lumen extending through the needle cannula, and an elongate sheath. The sheath comprises a longitudinal sheath lumen through which the notched needle cannula is slidably disposed, where the sheath includes a generally cylindrical body defining the sheath lumen. The body including a coiled coated-wire tube extending proximally from a distal body end, a sheath (180) overcoating around the coiled coated-wire tube, and where the coiled coated-wire tube and the needle cannula each has a substantially consistent outer diameter along its entire length, and the sheath overcoating includes a first thickness along a distal sheath length, the sheath overcoating includes a second thickness along a mid-section sheath length, and were the first thickness is greater than the second thickness such that the first thickness causes an outer diameter of the distal sheath length to be larger than an outer diameter of the mid-section sheath length, the sheath overcoating includes a third thickness along a proximal sheath length, and where the third thickness is greater than the second thickness such that the outer diameter of the proximal sheath length is larger than an outer diameter of the mid-section sheath length.
