Robot-Assisted Kidney Transplantation (RAKT) has been shown promising results in grafts coming from living donation. However, this technique has two main limitations. First, grafts coming from cadaveric donors, usually reserved to patients with advanced systemic disease who often present iliac artery plaques, are excluded from RAKT because of the lack of intraoperative haptic feedback. For this reason, we introduced 3D imaging reconstruction in RAKT through the Augmented Reality (AR) in order to intraoperatively guide the surgeon, showing where to put the clamps and perform arteriotomy in the recipient iliac artery. Second, the regional hypothermia during rewarming time is guaranteed by intermittent ice slush insertion in the abdominal cavity, which may be suboptimal and increase the risk of ileus. To overcome this limit, we developed and tested a cold ischemia device with the aim to maintain a low and constant graft temperature while avoiding ice slush introduction.
These two projects were conducted according to IDEAL model for surgical innovation. In the first project, iliac artery anatomy together with plaques was represented in a 3D printed model. Firstly, this model was used in Open Kidney Transplantation (OKT) setting in order to test the accuracy of the 3D reconstruction, comparing it with intraoperative tactile feedback. Subsequently, we employed this technology in the AR setting, in two cases without plaques. Finally, we tested AR in a patient with plaques. In the second project, the cooling device was developed and tested in an ex-vivo setting to assess its cooling performances. In phase 2a, the device was used in an in-vivo porcine model to evaluate the feasibility to perform both a complete OKT and RAKT. Finally, in phase 2b, CID was employed in 4 patients undergoing OKT or RAKT from living donors. Graft temperature was monitored using a thermal probe inserted between the device and the graft.
The 3D-AR enabled to clamp the artery in the correct position and to find the right place to perform arteriotomy. Phase 2 demonstrated that both OKT and RAKT can be performed with the support of CID in a clinical setting, without any modification in our standard technique or perceived lengthening of the operative time. Graft temperature never exceeded 20°C. No complications related to the use of both these devices were recorded.
These new tools were designed to overcome RAKT’s main limitations, optimizing the graft cooling system and including patients with atheromatic vascular disease, paving the way to expand the indications of RAKT.