科研之友
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摘要
Background and Objective The optimal fiber manipulation during laser prostatectomy has been highlighted as a critical element to achieve desirable clinical outcomes. However, scientific understanding of the physical interplay between fiber movement and ablative tissue response is still lacking. The objective of this study was to quantitatively investigate the effect of angular movement of an optical fiber on tissue ablation performance. Study Design/Materials and Methods Porcine kidney was employed as a tissue model in vitro. A 180?W 532?nm surgical laser with 750?mu m side-firing fibers was utilized to mimic clinical laser prostatectomy. The effect of fiber manipulation parameters on the tissue such as irradiance, number of overlapping pulses (OP), and beam path length (BPL) was assessed at various fiber sweeping (rotational) angles ranging from 0 degrees to 120 degrees. Morphological properties of the post-irradiated tissue were also evaluated in light of ablation depth, coagulative necrosis, and volumetric ablation density (VAD). Results As sweeping angle (SA) increased, both laser irradiance and number of OP decreased but BPL increased. Ablation depth was maximized (5.4?+/-?1.0?mm) at SAs less than 30 degrees but decreased at higher SAs. The SAs of 15 degrees and 30 degrees demonstrated the minimal thickness of denaturized tissue (0.74?+/-?0.14?mm) and VAD (total laser energy/ablation volume (AV)approximate to.6?+/-?0.46?J/mm3). Decreasing depth and increasing tissue coagulation associated with increasing SA resulted from substantial reduction in both beam irradiance and number of OP, eventually impeding ablation process. Excessive tissue denaturation also occurred when no rotational motion was applied to the fiber possibly due to plume shielding. Conclusion Inefficient tissue ablation could lead to adverse post-operative complications due to unwanted thermal injury to peripheral tissue. A SA of 30 degrees was found to be desirable for effective tissue ablation, and further clinical investigations will validate the current findings. Lasers Surg. Med. 44: 653663, 2012.
- 出版日期2012-10
