Dynamic prostatic and laser-ablated lesion volume change after transperineal laser ablation in canine: preliminary observation and its clinical significance.

ABSTRACT

AIM: The purpose of this study is to observe the volume change of prostate and laser-ablated lesions in the canine and to explore the mechanism and clinical significance through histopathology. MATERIALS AND METHODS: Transperineal laser ablation (TPLA) was performed under the guidance of transrectal ultrasound (TRUS) in eight canines. Two canines were sacrificed 1 day and 1 week after TPLA, respectively. The remaining six canines were sacrificed after finishing transrectal contrast-enhanced ultrasound (TR-CEUS) at three phases. RESULTS: The prostatic volumes immediately following TPLA and 1 week later were larger than before TPLA (20.1 ± 3.9 vs 17.1 ± 3.8 ml; 21.7 ± 3.6 vs 17.1 ± 3.8 ml, p < 0.05), but 1 month later, returned to the preoperative level (17.4 ± 3.2 ml). At three time points, the mean volumes of laser-ablated lesions at 3 W/600 J were 0.6 ± 0.2, 1.1 ± 0.4, and 1.7 ± 0.5 ml, respectively, while those of laser-ablated lesions at 3 W/1200 J were 1.2 ± 0.2, 1.6 ± 0.3, and 2.2 ± 0.5 ml, respectively. The mean volumes of laser-ablated lesions increased significantly over time after TPLA (p < 0.050). CONCLUSION: The prostate volume transient enlarges after TPLA, which prompts for clinical application that it should prolong appropriately the duration of urinary catheterization to avoid acute urinary retention. Many inflammatory cells were observed in the laser-ablated lesions and adjacent normal prostate parenchyma through histopathology. It is speculated that the inflammatory response is involved in the progression of tissue damage.