A new laser technique that could significantly reduce scarring after surgery has been discovered by researchers at The Hospital for Sick Children (SickKids) and the University of Toronto. The scientists compared a new surgical laser called Picosecond IR Laser (PIRL) to conventional surgical lasers and traditional surgical tools, such as scalpels. They found that using the PIRL in mice resulted in minimal scarring; in fact, the scars that resulted from this technique were half the width of those produced by traditional methods. The wounds also appeared to heal faster with PIRL surgery. (A) The mechanical scalpel cuts skin by producing shear forces which exceed the elastic limit of the tissue. This causes a border of damage around the incision which reaches as far as 400 µm from the borders of the incision. (B) Conventional surgical lasers cut by depositing heat until the tissue melts or burns away. The damage zone in this case, can reach up to 800 µm away from the ablated edge. (C) By contrast, the well absorbed PIRL pulses cause superheating of water inside the tissue on the picosecond timescale, ejecting the tissue faster than energy can diffuse to the surroundings area. The remaining adjacent tissue shows minimal damage compared to the other two modalities. (Image: © 2010 Amini-Nik et al./PLoS ONE) “Achieving minimal scarring is beneficial to patients, especially in cases where scarring can be particularly debilitating,” said Dr. Benjamin Alman, co-principal investigator of the study, head of the Division of Orthopaedic Surgery, senior scientist at SickKids, and A.J. Latner professor and chair of Orthopaedic Surgery at the University of Toronto. “By reducing healing time this new surgical method could also result in increased patient comfort and lower risk of secondary infections due to surgery.” The study’s co-principal investigator is University Professor Dwayne Miller of the Departments of Chemistry and Physics and the Institute of Optical Sciences at the University of Toronto. Lasers are known for their precision, but they have been limited in their use as a surgical tool because in many cases, the laser is more damaging to surrounding tissues than cutting with traditional surgical tools. “One of the major stumbling blocks in using lasers for surgery is the collateral damage that is usually caused by thermal and shock waves to the area,” said Alman. “Traditional lasers tend to burn the tissue, but PIRL superheats the cutting area quicker. It vaporizes the tissue, resulting in less destruction to the cells.” Researchers say this new technique looks promising and clinical trials in adult patients could take place as early as next year. Alman’s lab will be relocated to the Cancer, Stem Cells & Regenerative Medicine neighborhood in the new SickKids Research & Learning Tower, which will encourage interactions with colleagues from other scientific disciplines. The study is supported by the Collaborative Health Research Projects Program of the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada and SickKids Foundation. The study appeared in the September 28 online edition of PLoS ONE. For more information, visit: www.buildsickkids.com