Lasers and other light technologies can be applied to a wide variety of open, minimally invasive (e.g. laparoscopic) and robotic surgeries in general surgery and other surgical disciplines. Laser light can be very highly focused and precise, making these devices desirable for cutting tissue in place of a scalpel. Lasers can seal lymph vessels to reduce swelling, limit the spread of bacteria and tumor cells, and shrink or destroy tumors and other lesions.


“These sophisticated devices produce highly precise and controllable effects on tissues,” explains Dr. Raymond J. Lanzafame, a board-certified surgeon, expert in laser applications and research and past president and current CME director for the American Society for Laser Medicine and Surgery.“Each laser wavelength has a characteristic effect on tissue based on the degree to which the light energy is absorbed, scattered, reflected or transmitted through the tissues and how the energy is delivered to the intended target tissue. The combination of the laser tissue interaction and the selection of the appropriate delivery systems and laser parameters determines the ultimate effects of laser use on the conduct and outcomes of surgery.”

Lasers allow the appropriately trained and skilled surgeon to accomplish more complex tasks, reduce blood loss, decrease postoperative discomfort, reduce the chance of wound infection, decrease the spread of some cancers, minimize the extent of surgery in selected circumstances and result in better wound healing.

So the overall advantage of the use of lasers in surgery is the ability to improve patient outcomes. In general, with the appropriate use of laser technology, the patient experiences less pain, bleeding, swelling and scarring, plus a reduced risk of infection. Ultimately, with these advantages, the length of the recovery period should be shorter and the patient is able to return to normal activities faster.

The majority of so-called “laser surgeries” actually use the laser device in place of other tools such as scalpels, electrosurgical units, cryosurgery probes, or microwave devices to accomplish a standard procedure like mastectomy (i.e. breast surgery) or cholecystectomy (i.e. surgical removal of the gallbladder). The surgeon’s understanding of safety procedures and proper training are critical. The benefits are considerable, if the laser is used appropriately by a skilled and properly trained surgeon.

Applications of lasers in surgery
The earliest applications for lasers in surgery occurred in the areas of ophthalmology and dermatology. LASIK surgery is perhaps the most best known laser application in ophthalmology, but lasers are also used to treat detached retinas, glaucoma and diabetic retinopathy. The dermatological use of lasers and other energy-based devices spans from the vastly increasing applications for cosmetic procedures to the treatment of port-wine stains, melanomas and scars due to traumatic injury. Currently, the CO2, holmium, thulium, KTP, KDP, LBO, Nd:YAG, and high power diode laser technologies are available for use in soft tissue applications. Laser technology is also available for lithotripsy.

Common uses for surgical lasers include:
• Neurosurgery, with precision cutting and endoscopic guidance in the brain and spinal cord
• Urology – treatment of urinary stones, bladder obstructions and enlarged prostates
• Dental applications such as drilling cavities, gum surgery, antibacterial treatments and tooth decay detection with optical coherence technology OCT imaging
• Gastroenterology, for management of obstructing and bleeding tumors and vascular malformations
• Gynecology, for treatment of cysts, endometriosis and fibroid tumors
• Otolaryngology, for treatment of lesions of the nasal passages, paranasal sinuses, larynx, and trachea.

The photons from a CO2 laser can be carried via hollow tubes, waveguides and mirrors. The OmniGuide fiber is a flexible chalcogenide glass waveguide that has been utilized for otolaryngological and neurosurgical procedures. “The potential exists for broader clinical use including various general surgical procedures,” states Lanzafame.

“The laparoscopic use of this wavelength is possible with the use of a focusing cube and an operative laparoscope, or with a variety of waveguides designed for multi-puncturelaparoscopic applications. The OmniGuide overcomes some of the problems associated with free beam and rigid waveguides due to its small diameter and flexibility, which more emulates a true fiber. The availability of these highly flexible devices has resulted in resurgence in the use of carbon dioxide laser energy for neurosurgical and otolaryngologicalprocedures including microsurgical applications.”

Thulium laser technology has recently become available for use with the da Vinci Surgical Robotic System from Intuitive Surgical, using the RevoLix system from LISA Laser USA. The robotic platform is fitted with a flexible introducer that is capable of accepting up to a 5F (1.67mm) diameter fiber.

According to Lanzafame, “The system is currently being marketed to gynecologists. However, the platform is certainly capable of much broader use in minimally invasive surgery.” Some of the most exciting advances for lasers and energy-based devices have taken place in the area of cancer treatment. Applications include the use of these devices for tumor resection or ablation as well as in combination with drugs for photodynamic
therapy, and interstitial thermotherapy. During Laser-induced interstitial thermotherapy (LITT), laser light at the tip of an optical fiber raises the temperature of the tumor cells and damages or destroys them. The FDA cleared an LITT device for use in neurosurgery in 2009.

Photomedicine
In addition to the use of lasers in surgery, the application of lasers and energy-based devices extends into in the area of photomedicine, which includes Photodynamic Therapy and Photobiomodulation.

Photodynamic therapy (PDT)
A drug, called a photosensitizer (which is a substance that sensitizes an organism, cell, or tissue to light), is injected into a patient and absorbed into cells in the body, staying longest in the cancer cells. Laser light is then used to activate the agent and destroy the cancer cells. PDT is usually used to treat tumors on or just beneath the skin, or on the lining of internal organs or cavities. Areas of treatment include pre-skin-cancers, esophageal cancer, and non-small cell lung cancer.

According to the National Cancer Institute, clinical trials are being conducted to evaluate the use of PDT for cancers of the brain, skin, prostate, cervix and peritoneal cavity. Also under development are more powerful photosensitizers, ways to more specifically target cancer cells and the delivery of the activating light.

Photobiomodulation
Photobiomodulation (PBM) also known as low level light therapy (LLLT) was first developed in the 1960s. It is a form of photonic therapy that utilizes non-ionizing light sources, including LASERS, broad band light, and LEDs in the visible and infrared spectrum that result in therapeutic benefits including alleviation of pain or inflammation, immunomodulation and promotion of wound healing and tissue regeneration. PBM is a non-visual, non-thermal process.

In this therapy, light energy (photons) penetrates tissue, where it interacts with chromophores located in cells, resulting in photophysical and photochemical changes that lead to alterations at the molecular, cellular and tissue levels of the body. Light induces a complex chain of physiological reactions in diseased and damaged tissues to accelerate wound healing and tissue regeneration, increase circulation, reduce acute inflammation, reduce acute and chronic pain and help restore normal cellular function. Interestingly, recent research indicates that light can enhance performance in normal tissues and cells.


PBM has been used as an effective tool to accelerate post-surgical healing. Dr. Juanita J. Anders, a professor of anatomy, physiology and genetics, and neuroscience at Uniformed Services University of the Health Sciences in Bethesda, Maryland, expert in photobiomodulation and current president of the ASLMS, comments, “We’d really like to see a broader adoption of the or laser therapy, because now there are a number of light devices that are being used to stimulate cell and tissue processes. We feel that the name photobiomodulation better describes the underlying mechanism.”

“Unfortunately, there is not mainstream medical acceptance of the use of photobiomodulation yet,” Anders explains. However, photobiomodulation is being used successfully pre-clinically and clinically in a broad range of applications including: wound healing and tissue repair, pain treatment, alteration of inflammation, and treatment of diseases and injury of the nervous system.

“With the application of light for PBM, it is important to get the dosage right; that is, the power density that is delivered and the time that you treat,” states Anders. “When you think about light, think about it as if you are using a drug, think about the dose of application.”

When going deeper into the tissue, “the wavelength is the determiner of the depth of penetration of the light. The output power that you use will determine the number of photons that are delivered at any point along the depth of penetration for a given wavelength.”

The field of PBM is expanding from wound healing and tissue repair to work in neurodegenerative diseases, such as Alzheimer’s and Parkinson’s Diseases. An exciting development is Transcranial Laser Therapy (TLT), which is the noninvasive delivery of near infrared laser energy to the brain for the treatment of acute brain injuries such as post-traumatic stress disorder, chronic neurological diseases, and mental illnesses.

Perhaps the most talked about recent development in PBM is in the dental field. Praveen Arany, a researcher at the National Institute of Dental and Craniofacial Research in Maryland, has discovered that laser light applied to a tooth can stimulate stem cells to produce dentin that restores the health of the tooth. This discovery is now moving into the clinical trial stage.

Safety
With the myriad uses for lasers and other light-based devices in medicine and surgery, there is one factor which remains constant; the critical need for the implementation of safety measures and appropriate training for physicians and staff performing the procedures.

“The surgeon should have a complete working understanding of lasers, their delivery systems and their tissue effects prior to attempting to apply them clinically,” states Lanzafame. “The surgeon must be aware that all lasers and delivery systems are not alike and that attention to the selection of the proper wavelength, delivery system and laser parameters are central to achieving the desired clinical endpoint, given the appropriate technical expertise. An intimate understanding of the details of the procedure, as well as the laser technology and delivery systems selected for use, is critical for the safe use of these technologies.

The surgeon and the entire surgical team should understand and implement safety procedures as recommended by the ANSI Z136.3 2011 Standard for Safe Use of Lasers in Health Care (Laser Institute of America, Orlando FL) and other appropriate regulatory bodies. Implementation of these guidelines in facilities and venues wherein lasers and light based technologies are being used will prevent injury to patients and personnel.”

Armed with the proper training and knowledge of safety procedures, surgeons can benefit from the high degree of precision and control laser devices provide. Lasers and other light sources can improve efficiencies and yield improved outcomes for the patient.

About the author: Andrea Alstad is the marketing and communications coordinator for the ASLMS, which is the largest multi-disciplinary professional organization dedicated to the development and application of lasers and related technology for health care applications. Currently, ASLMS has over 4,000 members, including physicians and surgeons representing more than 51 specialties, physicists involved in product development, biomedical engineers, biologists, nurses, industry representatives and manufacturers.

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