Learning objectives
1. Demonstrate utilization of curved needle technique with CT, ultrasound, and MRI guidance. 2. Demonstrate custom curving of spring loaded core biopsy device. 3. Demonstrate utilization of custom curved needle for liver tumor ablation applications
Background
Over the last 25 years, image guided interventions have come to play a key role in the diagnosis and management of disease. Many techniques have been developed to enable percutaneous needle access to deep structures within the body using ultrasound, CT, or MRI guidance. However, some targets are still not directly accessable. In such instances, one may consider the curved needle strategy. Approaching a target with a curved needle can enable the operator to avoid sensitive structures, sample different parts of a lesion through the same guide needle, and compensate for suboptimal positioning of a guide needle.
Imaging findings OR Procedure details
Applications of this technique in the literature for fine needle aspiration biopsy and drainages will be reviewed. We will also describe our experience using this strategy not only for fine needle aspirations but also for core biopsies using spring-loaded devices, and for ethanol injection therapy and radiofrequency ablation of liver masses. We will demonstrate how customized curves can be generated from conventional straight needles, spring-loaded biopsy devices, and ablation electrodes. Cases illustrated will include coaxial core biopsies of otherwise inaccessible targets, and of lesions where sampling yield was enhanced. For liver tumor ablations, cases illustrated will include utilization of the curved needle to better access difficult lesions for ethanol injection therapy, as well as radiofrequency ablation. Guidance for the curved needle by CT, ultrasound, and MRI will also be demonstrated.
Conclusion
A thorough understanding of the curved needle and how this tool is applied in pursuit of a variety of diagnostic and therapeutic objectives enables the interventionalist to maximize safety while accessing lesions with image guidance that would otherwise be inaccessible.