Performance of a New Blunt-Tip Needle for the Displacement of Critical Structure in Thermal Ablation

To ascertain the performance of a new blunt-tip needle (HydroGuard^®), which allows injection of fluids during needle advancement in order to safely approach, displace and insulate nearby critical structures during thermal ablation (TA).

This study included 27 consecutive patients treated by TA [cryoablation (CA), radiofrequency (RFA), and microwave MWA)] between April 2018 and January 2019. During TA, hydro- or gas dissection was performed with HydroGuard^® needle to displace and protect critical structures close to the tumor (< 10 mm). Technical and clinical success, distance between critical structure and tumor before and after hydro/gas dissection and complications were recorded.

Eighteen patients were treated by CA (66.7%), 7 by MWA (25.9%) and 2 by RFA (7.4%). Majority of patients were treated with a curative intent (24/27; 88.8%). Adjacent critical structures include vessels (n = 3), nerves (n = 10), ureter/renal pelvis (n = 3), bowel/rectum (n = 10), stomach: (n = 3), diaphragm (n = 2), and pleura (n = 1). Technical success was 100%. Clinical success was 88% (24/27). Median minimum distance to adjacent critical structures before hydro/gas dissection was 1 mm (range 0-9 mm; IQR: 0-3 mm) versus 10.5 mm (range 4-47 mm; IQR: 9.7-18 mm) after displacement. Of the 27 patients treated, four developed complications (14.8%; 95% CI: 1.4-28.2): 1 major (3.7%; 95% CI: 0-10.8) and 3 minors (11.1%; 95% CI: 0-23). Only one minor complication was related to inadequate hydro-dissection, resulting in close proximity of the critical structure to the ablation zone.

HydroGuard^® is a safe and effective needle when used to approach, displace and insulate nearby critical structures during TA.