Directable Needle Guide: Efficacy for Image-Guided Percutaneous Interventions

Diagnostic and therapeutic image-guided percutaneous interventions have become increasingly important in the clinical management of various conditions. Though precise needle placement via a safe route is essential for successful percutaneous interventions, it is often difficult in cases of deeply situated, small lesions. The present paper describes the efficacy of the directable needle guide (DNG), which allows manipulation of the direction of a fine needle within organs. The DNG was used in patients for needle biopsy of hepatic ( ) and splenic ( ) lesions and for percutaneous ethanol injection therapy for liver tumors ( ) under sonographic or computed tomography guidance. The DNG enabled the direction of a 21- or 22-gauge needle to be successfully changed during needle advancement in all cases, allowing adjustment of the location of the needle tip or needle access root to avoid vessels, the gallbladder, and the lungs. We conclude that DNG increases the safety and ease of percutaneous interventions. 1. Introduction Image-guided percutaneous interventions with a fine needle are used for various clinical purposes, including biopsies, antitumor therapy with ethanol injection, laser thermal ablation, gene-technology implants, and nerve blocks [1–4]. Though precise needle placement passing through a safe root is essential for percutaneous interventions, it is often difficult due to needle deflection and patients’ respiratory or postural variations during the procedure and also because of intervening vital structures on the root. When a thin beveled needle is inserted into any organ, the tip of the needle has a tendency to curve toward the side when advancing, due to its flexibility. However, when a beveled needle is inserted with a twisting motion, it advances in a straight path. This phenomenon was applied to create a directable needle guide (DNG) that could be used to steer a needle within organs. The present paper describes the utility of the DNG in our clinical experience. 2. Subjects and Methods The DNG was used in patients undergoing both needle biopsy of hepatic ( ) or splenic ( ) lesions and percutaneous ethanol injection therapy for liver tumors ( ). Sonography and computed tomography (CT) images were used for imaging guidance in 43 and 17 lesions, respectively. The DNG (0.018 inches in diameter; 250？mm long) with a flattened segment (0.010 inches in thickness) on the distal portion of the beveled side of the tip (Leadway, Hakko, Tokyo, Japan, a prototype not commercially available at present) (Figures 1(a) and 1(b)) was used to direct the needle