Therapeutic Ultrasound and the Integration of Skin Grafts

Title: Can Therapeutic Ultrasound Influence the Integration of Skin Grafts
Author: Adriana da Costa Goncalves
Source: Ultrasound in Medicine and Biology Sep2007, Vol. 33 Issue 9 p1406-1412

Autogenous skin grafting is the most common skin graft procedure used. It can be implemented in a wide variety of circumstances from burns to reconstruction. The skin grafts usually heal on their own, except for in cases when tissue necrosis and eventual rejection of the entire graft occurs. In this case the area must be grafted again or another plan of action must be attempted. Since therapeutic ultrasound has been shown to effectively heal and regenerate skin, bone, muscle, tendon, and peripheral nerve tissue scientists are trying to explore if it can be used in accelerating skin graft integration.

The use of ultrasound in skin graft integration was done in a trial consisting of twenty female New Zealand rabbits. The rabbits received a skin graft in the dorsal region. The graft was covered over with a tie-over Brown type dressing for three days which was then removed to allow therapeutic ultrasound. In some cases the therapeutic ultrasound was done over the entire graft. In others the graft was divided into two parts, one that received the ultrasound (group 1) and one that only received the manual massage of the ultrasound head but not the actual ultrasound (group 2). After eleven days the animals were killed and the skin grafts were removed for study.

Results showed that there was no significant difference between the epidermal and dermal area between group 1 and 2 after eleven days. However it was observed that there was a significant increase in proliferating cells in group 1 at 12.18% compared to the 7.34% of group 2. It also showed that there was a significant amount of new blood vessels in the reticular layer of the dermis in group 1 compared to that of group 2. It was also observed that after 35 days there was no visible difference between group 1 and group 2.

The biological mechanism of ultrasound in the integration of skin grafts is still not entirely clear. However, the increase in proliferating cells and new blood vessels points to better integration. Yet, like in all animal testing the difference in rabbit and human skin must be taken into account. The results in the rabbit trials do suggest that human trials should take place.

If ultrasound proves to be effective in humans it could be very important to skin graft surgery. It could be used in graft rejection, since we still don’t really know why autologous grafts are rejected in the first place. It could solve the problem of having to regraft or not being able to graft on a particular person. Also, if it can help in integration, it could speed up recovery time, allowing patients to get out of the hospital and back to normal life faster, and ultimately cutting down on costs.