Supine CT-Guided Posterior Approach Using a Dorsal-Space Mat: Initial Clinical Experience and Geometric...

To evaluate the clinical feasibility, safety, and geometric characteristics of a supine CT-guided posterior approach using a custom dorsal-space mat in patients for whom the supine position was required or preferred.

This retrospective study included 16 consecutive patients prepared for the approach. Puncture trajectory parameters, positional stability, technical success, procedure time, and adverse events were evaluated in successfully positioned patients (n = 15; 35 trajectories). A geometric model was constructed to estimate maximum allowable puncture angles determined by mat height, needle length, and table geometry.

Positioning feasibility was 15/16 (93.8%); one patient was converted to a lateral approach due to shoulder pain. Technical success was 100% per patient (15/15) and per trajectory (35/35). The mean puncture angle and depth were 40.2° ± 9.1° and 8.3 ± 2.5 cm, respectively. All puncture angles were within theoretical geometric limits, with a mean angular margin of 14.9° ± 10.9°. Quantitative stability assessment was feasible in 14 patients; median two-dimensional displacement and absolute axial rotation were 4.1 mm (IQR, 3.3-4.5 mm) and 0.9° (IQR, 0.3-1.2°), respectively. Between-group differences observed in the trajectory-level analysis were not statistically significant in the patient-level sensitivity analysis. One Grade 5 adverse event occurred after RFA; although a relationship with the procedure could not be excluded, it was unrelated to the mat or puncture trajectory.

This preliminary feasibility study suggests that the dorsal-space mat can provide sufficient working space for CT-guided posterior procedures while maintaining the supine position. Larger prospective studies are required to establish its broader clinical applicability and safety.