Needle track ablation

Nevertheless, based on the principle of cauterization, the coagulative potential of the thermal ablation procedure itself makes the bleeding of a treated lesion quite unusual. To avoid needle track bleeding it is recommended to perform hot probe repositioning and removal (i.e. needle track ablation). Therefore, regarding the present literature bleeding in total is a rare, in most cases self-limiting, complication with a frequency of no more than 2%. 

Future advances include the automation of registration, which could further streamline clinical translation of such technologies. Miniaturization of internalized sensors for electromagnetic tracking of needles and ablation probes will have the ability to transform image-guided needle-based procedures by providing real-time multimodality feedback. 

In larger lesions, the array is withdrawn and redeployed anteriorly at 1.5- to 2.0-cm intervals into the tumor. After the hooks are fully deployed, the electrode is connected to the RF generator. The heating protocol for all the available needles is provided by the manufacturer. In general, the generator is started at a lower power setting and is subsequently increased in 10-W increments at 1-min intervals. The endpoint of RF application is the appearance of a rapid increase in tissue impedance (Roll-off) around the electrode. When this occurs, the RF application is automatically terminated. This process is repeated starting at 70% of the roll-off power until a second increase of the impedance occurs. Since the time point of the rapid increase in tissue impedance cannot be predicted, the ablation time needed varies dramatically between different tumor sizes and nodules. At the end of the procedure the needle track is ablated to prevent any tumor dissemination. Therefore, the tip has to be unisolated prior to the insertion of the needle. 

---