Bulletin Autumn‧Winter 1996

Improved Skin Graft ing Techniques Br ing Hope to Burn Patients T he skin is an important organ for r egu l a t i ng b o d y t empe r a t u re an d general protection. It consists of t he epidermis, an outer layer abou t 0.07mm thick, and the dermis, an i n n e r l a y e r measu r i ng b e t we e n 2.05 and 5mm. When the dermis is seriously b u r n t , it n o t o n l y causes a lot of pain , but renders the woun d vulnerable to bacterial invasions. Without this natural barrier, any small amount of bacteria can easily get into the bloodstream and be carried to the internal organs, and the patient may eventually die from complications. According to a survey conducted last year, the Prince of Wales Hospital has been treating approximately 200 burn patients a year, of w h om 19 per cen t need surgery, and 7.7 per cent are in life-threatening conditions. As the damaged dermis cannot restore itself, treating bums is very difficult. The usual procedure for treating bums is to graft healthy skin from othe r parts of the patient's body onto the wound after disinfecting the area. I n patients with extensive and deep burns, donated skin, pig' s skin or artificial s k i n is u s e d to p r o t e c t t he w o u n d temporarily, wh i l e a tiny skin sample taken f r om the p a t i e nt is c u l t u r ed i n t he l abo r a t o r y . Us i ng a s o p h i s t i c a t e d c e l l culture technique, the skin sample can be grown to 200 times its original size in three to four weeks. When the c u l t u r ed s k i n is of adequa te size — usually at 50 to 100 times the original size — it is ready for transplantation. T h e L i m i t a t i o ns o f Cu l t u r e d S k i n Compared to natura l skin, cultured skin is very fragile, consisting of only five to six layers of cells. Since it has no dermal layer, the wound remains susceptibl e to infection. Cultured ski n also falls off easily if the surface of the wo u n d is not clean. Hence, danger to the patient's life exists even after skin grafting. At the Department of Surgery of The Chinese University of Hong Kong, Prof. Walter W.K. King, Prof. Arthur K.C. Li and Mr. P.K. Lam (now an employee of the A patient seriously b u r n e d b y chemicals Improved Skin Grafting Techniques Bring Hope to Burn Patients 25