Evaluation of a nitinol stone retrieval basket as an alternative to biopsy forceps for biopsy of suspected upper tract genitourinary malignancies.

Background: The anatomical nature of the ureteroscopic approach for biopsy of upper urothelial tract tumors requires the utilization of small instruments, often limiting biopsy specimen quality. This leads to lower-than-desired tumor grading accuracy and malignancy detection capabilities on the initial evaluation of upper tract tumor specimens. This is problematic because optimal treatment of upper tract urothelial carcinoma (UTUC) depends on early disease detection and subsequent accurate diagnosis. Objective: The objective of our study was to compare the biopsy capabilities of two ureteroscopic biopsy instruments - biopsy forceps and the nitinol stone retrieval basket. Methods: We performed a retrospective analysis of ten patients who underwent biopsy of an upper tract mass with either instrument. Average specimen size, muscularis propria presence, and malignancy detection sensitivity were the variables of interest. Results: The nitinol stone retrieval basket obtained larger biopsy samples than the biopsy forceps, with average biopsy volumes being 0.0674 cm3 and 0.0075 cm3, respectively (P = 0.00017); this was the only statistically significant result of our study. Muscularis propria was present in 31% (4/13) of the biopsies with the nitinol stone retrieval basket, whereas 0% (0/5) of the biopsy forceps biopsies contained muscularis propria (P = 0.2778). Regarding malignancy detection sensitivity, the nitinol stone retrieval basket biopsies identified malignancy in 100% of the specimens that had confirmed malignancy; the biopsy forceps only detected malignancy 40% of the time (P = 0.4134). Conclusion: These findings suggest that the nitinol stone retrieval basket is a useful diagnostic tool for UTUC, although further investigation is warranted to determine its superiority compared to biopsy forceps.

Robotic-Navigated Percutaneous Pedicle Screw Placement Has Less Facet Joint Violation Than Fluoroscopy-Guided Percutaneous Screws.

OBJECTIVE: To directly compare robotic-versus fluoroscopy-guided percutaneous pedicle screw (PPS) placement in thoracolumbar spine trauma with a focus on clinically acceptable pedicle screw accuracy and facet joint violation (FJV). METHODS: A retrospective chart review assessed 37 trauma patients undergoing percutaneous thoracic and/or lumbar fixation. Postoperative computed tomography images were reviewed by authors blinded to surgical technique who assessed pedicle screw trajectory accuracy and FJV frequency. RESULTS: Seventeen patients underwent placement of 143 PPS with robotic assistance (robot group), compared with 20 patients receiving 149 PPS using fluoroscopy assistance (control group). Overall, the robot cohort demonstrated decreased FJV frequency of 2.8% versus 14.8% in controls (P = 0.0003). When further stratified by level of surgery (i.e., upper thoracic, lower thoracic, lumbar spine), the robot group had FJV frequencies of 0%, 3.2%, and 3.7%, respectively, compared with 17.7% (P = 0.0209), 14.3% (P = 0.0455), and 11.9% (P = 0.2340) in controls. The robot group had 84.6% clinically acceptable screw trajectories compared with 81.9% in controls (P = 0.6388). Within the upper thoracic, lower thoracic, and lumbar regions, the robot group had acceptable screw trajectories of 66.7%, 87.1%, and 90.7%, respectively, compared with 58.8% (P = 0.6261), 91.1% (P = 0.5655), and 97.6% (P = 0.2263) in controls. CONCLUSIONS: There was no significant difference in clinically acceptable screw trajectory accuracy between robotic versus fluoroscopy-guided PPS placement. However, the robot cohort demonstrated a statistically significantly decreased FJV overall and specifically within the thoracic spine region. Use of robotic technology may improve radiographic outcomes for a subset of patients or spine surgeries.