Robot-assisted laparoscopic radical prostatectomy (RALP) using daVinci®surgical robot system (Intuitive Surgical) has gained wide acceptance for the treatment of clinically localized prostate cancer. The preservation of the neurovascular bundle (NVB) including cavernous nerves during the surgery improves the postoperative recovery of sexual potency. However, NVB visualization can be challenging due to the periprostatic connective tissue and intraoperative hemorrhage. The accompanying blood vessels in the NVB, which are visible with Doppler ultrasound, can serve as a macroscopic landmark to localize the microscopic cavernous nerves in the NVB.
A novel robotic transrectal ultrasound probe manipulator (TRUS Robot) is used concurrently with the daVinci® in a tandem robot approach (T-RALP) to intraoperatively image the prostate and NVB. The TRUS Robot was developed to provide a steady holding of the TRUS probe and allow remote manipulation using a joystick located next to the daVinci® console.
Manual TRUS handling discards position data. But when the TRUS probe is manipulated by the robot its positional data is readily available. This allows for recording image-position data pairs for robot control and 3-D image reconstruction. The robot scans the prostate volume by rotating the TRUS probe about its axis.
The objective of the T-RALP approach is to use TRUS images for guiding the surgeon. A clinical study is curently in progress for the validation of the concept. Preliminary results are very promissing. The image below, for example, is a 3-D reconstruction of a prostate, urethra, and the NVBs. This figure shows a novel representation of the structure of the gland, never before represented as a combination of ultrasound and Doppler geometrically consistent imaging, as enabled here by the use of the robotic device.This is a 3-D model that can be interactivelly reorinted and scaled. It is best viewed with the latest Adobe Acrobat Reader.