Laser on Wound Healing

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Written By María Suárez Redondo DVM PhD CVA CVFT CVTP

Treatment of wounds on distal limbs can be challenging because of availability of local skin and optimal blood supply are limited. Integrating laser therapy into wound management is becoming more frequent and a very valuable help for chronic, large, infected wounds or conditions where wound healing is expected to be delayed.

Case: 15yo FS Belgian Shepherd dog is referred to the clinic for laser treatment of a chronic wound on the dorsum of the carpus, 8 x 6 cm in size. A fibrosarcoma had been removed from the site 4 months ago, with clean surgical margins according to the Pathology report. Dehiscence of the sutures had occurred several times, and the wound had not evolved for the last 11 weeks. The patient had a tend to local self-trauma and presented 3/5 lameness in that limb.

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Therapeutic laser has several effects, briefly: improvement in local circulation(1), increased tissue oxygenation and increased activity of the enzymes in the mitochondrial respiratory chain (2). This implies a faster wound healing rate and regeneration of skin with up to 80% more strength when compared to control groups (3). The improvement of local vascularization is, at least partially, mediated via VEGF (4).

In this case, a wound dressing with silver alginate was also used for the first 48h, to help remove potentially infected exudate (5). Laser has an anitimicrobial effect, both directly and due to local increase in tissue oxygenation. This is achieved within physiological temperature range and therefore without thermal damage to the skin (6).

Laser treatment also improves skin flaps and grafts´survival (1) and can be combined with surgical closure of wounds, although in this case the non-surgical approach was preferred and is especially interesting in geriatric patients.

Each session of treatment lasted less than 4 minutes. This modality is very well tolerated by the patients. The improvement of the lameness is related to wound healing, but the endorphin release in response to laser treatment could also be involved (7).

1. Kubota J. Effects of diode laser therapy on blood flow in axial pattern flaps in the rat model. Lasers Med Sci. 2002;17(3):146-53.
2. Wray S, Cope M, Delpy DT, Wyatt JS, and Reynolds EOR. Characterization of the near infrared absorption spectra of cytochrome aa3 and haemoglobin for the noninvasive monitoring of cerebral oxygenation. Biochimica et Biophysica Acta. 1988; 933:184-192.
3. Stadler I, Lanzafame RJ, Evans R et al. 830-nm irradiation increases the wound tensile strength in a diabetic murine model. Lasers Surg Med. 2011;28(3):220-6.
4. Tuby H, Maltz L, Oron U. Modulations of VEGF and iNOS in the rat heart by low level laser therapy are associated with cardioprotection and enhanced angiogenesis. Lasers Surg Med. 2006;38(7): 682-8.
5. Chuangsuwanich A, Chortrakarnkij P, Kangwanpoom J. Cost-effectiveness analysis in comparing alginate silver dressing with silver zinc sulfadiazine cream in the treatment of pressure ulcers. Arch Plast Surg. 2013;40(5):589-96
6.Bornstein E, Hermans W, Gridley S, Manni J. Near-infrared photoinactivation of bacteria and fungi at physiologic temperatures. Photochem Photobiol. 2009;85(6):1364-74.
7. Hagiwara S, Iwasaka H, Okuda K, Noguchi T. GaAlAs (830 nm) low-level laser enhances peripheral endogenous opioid analgesia in rats. Lasers Surg Med. 2007;39(10): 797-802.