Comparing different treatment modalities for partial nephrectomies without ischemic period: Laser, Hydro-Jet and RF

The treatment of partial nefrectomies is usually performed under a warm ischemic period. Recently, various treatment modalities have become available to perform a partial nefrectomy without clamping off the blood circulation. We have studied three devices in laboratory setting, investigating the thermal and high speed imaging techniques in tissue models and consequently, applying the instruments in the clinic during open procedures especially looking at efficacy and blood loss. The continuous wave 2.0 micron laser of 70 W (Revolix, LISA laser) is used as a fiber delivered knife cutting through circulated tissue with controlled hemostasis for vessels up to 3 mm diameter. The 2 μm wavelength effectively vaporizes tissue water and coagulates the smaller vessels. The Hydro-Jet (ERBE, Germany) uses high pressure (20-80 bar) to ejects a water jet of 40 um diameter at high velocity (10-30 m/s). The parenchyma is resected while vessels are preserved. Consequently, the exposed vessels can be coagulated in a controlled way with minimal blood loss. The water jet showed to induce cavitation bubbles that resect the soft tissue from the matrix leaving the elastic microvessels intact. Various systems are based on bipolar RF technology. We are using the Habib device (Rita 1500X RF generator) to create a coagulation zone around the tumor. Subsequently, the tumor can be resected along the coagulation zone with minimal bleeding. The treatment modalities investigated, have their own advantages and, stand-alone or in combination, can facilitate laparoscopic partial nephrectomies without an ischemic period.