Sviluppo di un sistema di coagulazione a microonde per l'impiego in chirurgia epatica miniinvasiva e robotica.

During the last two decades, many surgical procedures have been evolved from traditional open surgery to less invasive or minimally invasive surgery. This limited invasiveness has motivated the development of robotic assistance platforms used during the surgical intervention to obtain better surgical outcomes. Nowadays, the da Vinci robotic system is the commercial robotic platform mostly used for modern minimally invasive surgical applications. Even in the field of minimally invasive hepatic surgery the Da Vinci Platform has been used, but not widely as in other organs such as prostate or lower rectum. The reason of this low spread needs to be researched in many factors. One of the most important is the difficulty in bleeding control during hepatic robotic surgery. Bleeding from parenchyma transection during a robotic hepatic surgery in fact remains one of the most critical point affecting the low spread of hepatic robotic surgery and also affecting the postoperative recovery and long-term survival. In order to solve this problem various robotic devices with different types of energies have been proposed; however, each of these commercially available robotic tools lack in steerability, efficacy, or accuracy. The aim of this work was to “de-novo” project and evaluate the feasibility and performance of a new steerable microwave resection device (SMRD) intended for minimizing intraoperative blood loss during robotic liver resections. The new device operating at 2.45 GHz has been designed to accommodate the engineering constraints derived from its use for robotic surgery, in which a steerable head is required and the internal cooling of forced gas or water is undesirable. The device project, design, analysis, and optimization were addressed using the most advanced commercial electromagnetic and thermal solvers to achieve the best results. To experimentally validate the results of the numerical analysis, many ablations were performed on freshly explanted bovine liver by using a single device prototype with three levels of energy supplied to the tissue. During the ablation procedures, the time, temperature, and shape of the thermal lesion were recorded using thermocouples and an infrared thermos-camera. Ex vivo tests showed good agreement with the numerical simulations, demonstrating the validity of the simplifications adopted to deal with the complex phenomena involved in the extreme hyperthermia of a living tissue. The high performance, thermal reliability, and robustness of the developed device were also demonstrated along with the possibility of reducing operation time and blood loss. In this work, the da Vinci Research Kit (dVRK), namely the research version of the commercial da Vinci robotic platform, was used to manipulate the novel microwave device in a teleoperation scenario. The dVRK provides an open source hardware/software platform, so that the novel microwave tool, dedicated to hepatic prevention bleeding during hepatic resection surgery, was mechanically integrated on the slave side, while consistently the software interface was adapted in order to correctly control tool pose. Tool integration and control were validated through in-vitro and ex-vivo tests, meanwhile the coagulative efficacy of the developed tool in a perfused liver model has been proved during in-vivo test session. In conclusion, an innovative microwave (MW) tool for liver robotic resection has been realized and integrated into a commercially available surgical robot. The tool can be easily operated through the dVRK master console without limiting the intuitive and friendly use, and thus easily reaching the hemostasis of liver vessels.