• prostate;
  • focal therapy;
  • ablation;
  • technology


  • To evaluate side-effects, erectile function and capability to preserve adjacent tissues of bilateral focal prostate ablation using low-energy direct current (LEDC) in a canine model.

Materials and Methods

  • In all, 12 male Beagle dogs underwent bilateral focal prostate ablation using the NanoKnife™ LEDC system.
  • Three 19 G monopolar electrodes were transperineally placed on each side of the prostate under transrectal ultrasonographic (TRUS) guidance using a triangular probe array.
  • Intra- and postoperative side-effects were recorded. Erectile function was evaluated at baseline and 4–5 and 26–27 days after ablation.
  • The dogs were killed humanely at 7 (six) and 30 days (six) for gross and microscopic evaluation of the prostate and adjacent organs.


  • The median (range) prostate volume on TRUS was 12.1 (8.9–17.2) mL. The electrodes were placed at a median distance of 0.55–0.66 cm from the capsule, urethra and rectum.
  • All procedures were completed successfully and recovery was uneventful. There were no episodes of urinary retention.
  • All the dogs were able to achieve erections after ablation.
  • Pathological analyses revealed inflammatory changes in the ablation zone at 7 days and replacement by fibrosis at 30 days. On microscopic examination no histological injury to the capsule, urethra, rectal wall or nervous structures was identified.


  • In this study, bilateral focal prostate ablation using LEDC was safe and had a favourable side-effects profile limited to transient minor events.
  • LEDC ablation effectively spared adjacent structures as well as physiological functions in all the dogs.