PURPOSE-The principal risks of needle biopsy are hemorrhage and implantation of tumor cells in the needle tract. This study compared hemorrhage after liver and kidney biopsy with and without radiofrequency (RF) ablation of the needle tract.MATERIALS AND METHODS-Biopsies of liver and kidney were performed in swine through introducer needles modified to allow RF ablation with the distal 2 cm of the needle. After each biopsy, randomization determined whether the site was to undergo RF ablation during withdrawal of the introducer needle. Temperature was measured with a thermistor stylet near the needle tip, with a target temperature of 70°C-100°C with RF ablation. Blood loss was measured as grams of blood absorbed in gauze at the puncture site for 2 minutes after needle withdrawal. Selected specimens were cut for gross examination.RESULTS-RF ablation reduced bleeding compared with absence of RF ablation in liver and kidney (P < .01), with mean blood loss reduced 63% and 97%, respectively. Mean amounts of blood loss (±SD) in the liver in the RF and no-RF groups were 2.03 g ± 4.03 (CI, 0.53-3.54 g) and 5.50 g ± 5.58 (CI,.66 g), respectively. Mean amounts of blood loss in the kidney in the RF and no-RF groups were 0.26 g ± 0.32 (CI, −0.01 to 0.53 g) and 8.79 g ± 7.72 (CI, 2.34-15.24 g), respectively. With RF ablation, thermal coagulation of the tissue surrounding the needle tract was observed.CONCLUSION-RF ablation of needle biopsy tracts reduced hemorrhage after biopsy in the liver and kidney and may reduce complications of hemorrhage as well as implantation of tumor cells in the tract.PERCUTANEOUS image-guided needle biopsy is often performed in highly vascular organs or in tumors with rich macroscopic and microscopic blood supply. The principal risks related to needle biopsy are hemorrhage and implantation of tumor cells in the needle tract. Incidences of postbiopsy hematoma in the liver have been reported in prospective studies to be 18.3% after biopsy with a 2.0-mm Tru-cut needle (1) and 23% after biopsy with a 1.6-mm Jamshidi needle (2). Patients with cirrhosis or hepatic tumors are at greater (4) and injection of fibrin (5), gelatin particles and thrombin (6), gelatin sponge pledgets (7,8), fibrinogen and thrombin (9,10), or autologous blood clot in an attempt to promote clotting and hemostasis in the needle tract. Kim et al (11) reported animal studies of radiofrequency (RF) coagulation with use of the biopsy needle itself to deliver the RF energy.Transplantation of tumor cells along the needle tract after biopsy of a malignancy is also a risk. Incidences of needle tract implantation after biopsy of hepatocellular carcinoma have been reported in two recent series as 3.9% (12) and 5.1% (13). There are also published reports of subcutaneous seeding after fine needle biopsy of metastatic colonic adenocarcinoma (14,15) and metastatic pancreatic adenocarcinoma (16). The development of an effective, inexpensive, and technically simple method of cauterizing a coaxial needle biopsy tract could provide a soluti...