; J. Koller
Department of Burns and Reconstructive Surgery, University Hospital Bratislava, Ružinov Hospital Bratislava, Slovak Republic
Vyšlo v časopise:
ACTA CHIRURGIAE PLASTICAE, 52, 1, 2010, pp. 7-12
primarily damage the skin and nearby structures. However, on a secondary
level they can endanger all the systems in the human body. From this point of
view, the management of burns represents a sector of medicine where
a multidisciplinary approach is essential. Nevertheless, the basic and
inevitable prerequisite of successful treatment of burns represents
the treatment of the burn wound, where skin substitutes are still
to epidemiological studies (9, 14), in the Slovak Republic scald injuries are
the most frequent, mostly afflicting patients in lower age groups.
Partial-thickness scald burns in particular constitute one of the most frequent
indications at our workplace for the utilisation of a biological skin
substitute: porcine skin xenograft. Considering the high incidence of this type
of injury – amounting to 43% of
all burned patients admitted in the years 1989–1993 in Bratislava (9) – their use in reasonable and efficacious treatment
is of great importance.
MATERIAL AND METHODS
study considered data from 109 patients with fresh superficial and deeper
partial-thickness burns who were hospitalized at the Teaching Department of
Burns and Reconstructive Surgery of the University Hospital, Bratislava,
Ružinov Hospital, Slovakia during the years 2005–2007.
The study was approved by the Ethics Committee of Ružinov Hospital.
xenografts (SXG) have been used as biological skin substitutes at the
Department of Burns and Reconstructive Surgery since 1987. They have been
prepared for clinical use in the Central Tissue Bank (CTB), part of the
Teaching Department of Burns and Reconstructive Surgery Bratislava, Slovakia
where SXG preparation method has been performed according to the original method
of Moserová (1974) with some minor modifications. Porcine skin removed from
veterinary certified slaughtered pigs, stored at the temperature of 4°C, is
transported from the slaughter-house to CTB. Within 24 hours after slaughter,
under sterile conditions, the retrieval of the dermoepidermal grafts is
performed by electrical dermatome. After washing the grafts retrieved in a solution of chloramine,
lavage in antibiotic solution and lavage in cryoprotective agent, four small
samples (0.5 x 0.5cm each) are taken from each graft for bacteriological
checks. Then each graft is placed on sterile gauze with the dermal side up,
folded to create a maximum of four layers and sealed in a sterile
plastic bag. Prepared SXGs are placed in a deep-freezer appliance and
stored at a temperature of -80°C. If the sterility tests are negative,
according to Czech-Slovak Pharmacopoeia 4th Ed., the SXGs can be released for clinical
admission initial assessment of the depth and extent of burns is performed. To
estimate the extent of the burns (BSAB) the Lund-Browder chart is used. The
depth of the burn is expressed in degrees. When indicated for the xenograft
coverage, after disinfection of the wounds with Betadine all patients undergo
complete debridement of non-viable epidermis using blunt debridement (gauze)
under systemic analgesia; in the case of children with greater extent of burns
general anaesthesia is used. After obtaining a clean wound surface with
the dermis exposed (Fig. 1) the cryopreserved porcine xenografts
(defrosted rapidly in saline immediately before usage) are applied (Fig. 2).
Treated areas are then covered with tulle dressing impregnated with Vaseline,
gauze with silver sulphadiasine, dry gauze layers and elastic bandage. When
xenografts are placed over the joints of limbs, in particular with children,
Kramer splints are used. Systemic antibiotic prophylaxis is provided by
intravenous administration of penicillin in standard doses in cases with
negative history of penicillin allergy. Wound cultures are taken during initial
treatment and also regularly during the hospital stay. If the wound dressings
are not displaced and no complications occur, dressings are changed every 48
hours. The xenografts are left to adhere to the wound surface until they are
separated by means of transepithelial elimination (Fig. 3). The residual
defects (if present) are treated by application of topical antimicrobial agents
within the scope of the methods for the wound healing during the hospital
stay or on an outpatient basis.
The inclusion criteria
during this retrospective study were as follows:
patients were hospitalized during the
three-year period (from the beginning of the 2005 to the end of the 2007)
all patients sustained partial-thickness
(superficial and deep dermal) scald burns
all patients were admitted and treated
within the first 24 hours after injury
all patients were indicated for wound
coverage by biological skin substitutes
patients of every age were included, with
a wide range of burn extent and associated illness
Total number of patients healed within
14 days postburn and their mean healing time
Mean healing time of all patients
included in the study (total healing time)
Mean discharge time to outpatient
Total number of patients whose treatment
required operation - wound closure by skin autografts
healing time was defined as the time necessary to reach 95% of
re-epithelialization by each patient. All patients were discharged from
hospital discharge if outpatient management could be performed safely and
In total, 109 patients
were included in the study. Of these patients 59 were males (54%) and 50
females (46%). The male/female ratio was 1.16:1 for adults and 1.2:1 for
children. The mean age of the patients was 7.6 years (min.: 6 months, max: 80
years). The majority of the 109 patients were children (96 cases). The mean
BSAB was 13% (min.: 3%, max: 43%). All patients suffered burns caused by hot
liquids (water, tea, coffee, soup).
Number of patients,
sex, mean age, mean BSAB, minimal and maximal values (min/max.) and standard
deviations (S.D.) are shown in Table 1.
According to BSAB the
patients were divided into three groups:
below 10% (48
patients with mean extent 7.6%)
11–20% (45 patients
with mean extent 13.4%)
more than 20% (16
patients with mean extent 29.4%)
The results are
displayed in Table 2.
Healing within 14 days
Of the 109 patients, 78
(71%) patients healed within 14
days with a mean time of 9.6 days (S.D.: 3.2). One sample t-test
which compared mean healing times achieved within 14 days with the value of 14
days established the significant difference (p=0.0001<0.05) with
a level of significance of 0.05.
In the group with
extents larger than 20% the lowest proportion of patients healed within 14
days. This shows the correlation between the larger extents of burns and increased
healing times in this group.
Healing within 14 days
serves as an expression of the healing dynamics and as a parameter for
comparison with other studies focused on alternative treatment options.
Total healing time
In this category too
the values in groups with extents up to 10% and from 10 to 20% were almost
identical and within 14 days. In the group with extents more than 20% the mean value of total healing time
was 24.6 days, which is in accordance with the increased value of mean healing
time within 14 days in this group. In all the 109 cases the mean total healing time
was 15.1 days (S.D.: 11.6) with no significant difference between mean total
healing times and the value of 14 days (p=0.3>0.05).
As the treatment of
residual defects could have been performed, in many cases, on an outpatient
basis, the mean values of discharge time in each group were lower than mean
values of total healing time. Of the 109 patients in total the mean discharge
time was up to 10 days.
In four cases it was
necessary to perform tangential excision of the deep parts of the wounds and
coverage with split-thickness skin autografts or coverage of residual defects
of a larger extent, the spontaneous healing of which would require much
more time. In the group with extents up to 10% there were no operations. In the
group with extents from 10 to 20% one case of a seven-year-old girl
with BSAB of 13.5% was treated by surgery. Because of the wound deepening of
BSAB 3.5%, the tangential excision and temporary coverage with porcine skin
xenografts were performed on day 10 postburn. Skin xenografts were replaced by
split-thickness skin autografts in the second stage. The wound cultures at the
day of admission were sterile, on day 4 postburn sterile – after multiplication Staphylococcus aureus. Of
the 16 patients in the group with BSAB above 20% three cases underwent surgery,
which represented 18.7% of this group. In two cases (one girl and one boy, both
aged two with BSAB 22% and 23% respectively), tangential excision and coverage
with split-thickness skin autografts of BSAB 6% and 6.5% respectively were
performed. In one case (a two-year-old girl, BSAB: 21.5%) it was necessary to
cover the residual defects, which represented BSAB 2%, with split-thickness
Of the 109 patients
four underwent surgery, which represents
3.6%. The mean surface operated on was 4.5% TBSA (total body surface
We tried to compare our
results with those obtained at other workplaces, where different types of skin
substitutes have been used in this indication.
In Beverwijk, the
Netherlands, a retrospective study of the treatment of scalds by
glycerolised skin allografts was performed by Brans (3) and published in 1994.
Over a period of four years 45 patients with a mean age of 23 months, mean BSAB 10.2% (from
3% to 23%) were treated during the first 24 hours post burn. Of these patients
21 (47%) healed within 14 days. The better outcome of patients in this study,
who were given treatment for scalds involving skin xenografts (71%) can only
partially be explained by the lower mean age of the patients in the Dutch
study. The decisive factor may be the difference in the viability of these skin
results of other studies indicate that it is necessary for a bioactive
surface to be present, in order to accelerate re-epithelialisation through
contact orientation and stimulation of cell proliferation (4, 8). From this
point of view, and with regard to the results achieved, the partially retained
bioactivity of skin xenografts seems more advantageous.
It is also possible to
preserve skin allografts by deep freezing, which retains their viability.
However, utilisation is recommended in cases where integration of the dermal
component as a part of permanent wound closure is desired (5), because the
glycerol preserved allograft provides no viable coverage material and lacks the
beneficial effect of integration and vascularisation of viable allogeneic
In Copenhagen, Denmark,
a prospective randomised study was performed by Leicht (10) based on
a comparison of treatment of scalds by lyophilised alografts (LA) and by
open technique. Of 50 patients with scalds, 25 –
with the mean age of 1.4 years and mean BSAB 8.35% – received LA within the first 24 hours post burn. Of
these 25 patients, 15 (60%) healed within 14 days. Better results achieved in
the study with xenografts (71% healed within 14 days) could be partially
explained by the higher mean age (7.6 years), but as mentioned previously, it
is also the case that lyophilised skin allografts do not retain viability in
comparison with cryopreserved skin xenografts.
The parameters compared
are shown in Table 3.
For the coverage of
partial-thickness burns amnion obtained from the placentas of selected donors
is also being used. In 2007 Singh (13) compared the burn wound healing rate
between radiation sterilized amniotic membranes and glycerol preserved amniotic
membranes. Fifty patients with partial-thickness burns (41 of them with scalds,
the rest caused by flame) up to 70% of BSAB were selected in this study. The
wounds of each patient were divided into halves, one half treated with glycerol
preserved membranes and the second half with irradiated membranes. There were
no significant differences in the rate of healing between the gamma-irradiated
amniotic membranes and glycerol preserved membranes, indicating that there is
no adverse effect of gamma irradiation on the efficacy of the membranes. According
to the authors, in all the patients the membranes dessicated and separated in
10–14 days, leaving behind an epithelialized
surface. The exact results of the healing were not stated.
The use of allogeneic
cultivated keratinocytes as a temporary wound coverage is advantageous
mainly with IIb degree burns, where
the capability of keratinocytes to promote epithelialisation by releasing
growth factors and mediators of wound healing is combined with the ability of
epithelialization from the adnexal structures of the viable parts of dermis.
The “Viennese concept” is based on this approach, as published by Rab in 2005
early tangential excision of partial and
full thickness scalds (4–7 days after trauma)
coverage of partial thickness burns by
cryopreserved allogeneic cultivated keratinocytes
in scalded areas which have to be excised
to the subcutaneous tissue the coverage of autologous split skin grafts is
still the method of choice
The authors compared 22
scalded children with wounds tangentially excised and covered with cultivated
allogeneic keratinocytes on days 4–7
after trauma with 14 children who underwent the same procedure on days 4–7 after trauma but using split skin autografts. They
observed significantly lower volume of blood transfusion and significantly
better long-term results pertaining to hypertrophic scar formation in the group
of patients covered by cultivated allogeneic keratinocytes. Bearing in mind the
results achieved, the authors feel that the higher costs resulting from the
usage of keratinocytes are justified. The “Viennese concept” is promising
mainly for management of scalds in the period after the first 24 hours
subsequent to trauma, when the usage of temporary skin substitutes is more
risky because of possible infectious complications, which can in many cases
disable their application.
The lower incidence of
hypertrophic scars in the group of patients covered with cultivated allogeneic
keratinocytes as a long term result corresponds with the finding of
Ghaffari (7), who observed significantly lower amount of collagen produced by
dermal fibroblasts during cultivation with keratinocytes. He explains this with
reference to the presence of keratinocyte-derived collagen-inhibitory factors
(KD-CIFs) with the molecular weight 30–50
kDa, which are regulating type I collagen expression and synthesis in
There is a reason
to suppose that this regulation also takes place with other types of biological
skin substitutes with preserved viability of keratinocytes, which could be the
scope of further investigation.
In addition to
biological skin substitutes, other types of skin substitutes of different
origin and constitution are also used for coverage of partial-thickness burns.
1998 Ou (11) published a retrospective study of the treatment of scalds by
Biobrane. Over a period of 2.5 years 106
patients with scalds with an average BSAB of 12.5% were treated within 24 hours
post burn. With 24 of these patients coverage was aborted because of the low
adherence; 14 of them healed spontaneously. For the 10 remaining patients it
was necessary to perform coverage with split skin autografts. The cases of low
adherence and accumulation of exudate below Biobrane was explained by the
authors with reference to the presence of devitalised upper dermis. Therefore
they emphasised accurate initial diagnosis of the depth of burns because, in
their view, the best results can be obtained only on superficial
partial-thickness burns. Patients undergoing surgery represented 9.4% of all
patients in the study, while in the study with skin xenografts the figure was
3.6%. Neither proportion of healing within 14 days nor total healing times were
stated. The mean time of separation of the skin substitute was 11.1days
(between 3 and 18 days).
In the period
immediately after an injury, during initial treatment, it is very difficult to
make an exact differentiation between IIa and IIb degree burns. Therefore it appears more suitable to employ skin substitutes
with adherence capacity which is not influenced by this depth range.
On partial thickness
face burns a biosynthetic skin substitute, Transcyte, has been used to
comply with the changing irregular surfaces of the face. In a comparative
study (6) the usage of Transcyte was compared with open technique (Bacitracine
ointment). The authors observed significantly shorter healing times, shorter
time for wound-care and lower pain in the group treated with biosynthetic skin
Zajíček, 2008 (16),
reported on the usage of a new sterile commercially-available biological
cover derived from acellular pig dermis. It is distributed in dry form and can
therefore be kept in storage for a long time. Hydrated cover can be used,
among other indications, for the treatment of superficial and deep dermal
At present research is
still ongoing into a permanent skin substitute with a quality closest
to the ideal skin substitute (15):
long shell life
used off the shelf
prevents water loss
easy to secure
grows with child
applied in one
does not become
does not yet exist.
Resulting from these
ideal properties, the characteristics of a good wound dressing which can
be used to cover all burns in primary care can be derived (1):
maintain moist wound
retains close contact with the wound
easy to apply and
application and removal
lasts for 10 days
waterproof to allow
for washing and bathing
Many biological skin
substitutes comply with some of the above criteria. The appropriate choice
should depend on careful considering of the characteristics, indications for
use and also the price of each available skin substitute. Only with this approach it is possible to achieve
the goal – early wound closure of the best quality.
The retrospective study
proved the clinical efficiency of using skin xenograft for the treatment of
partial thickness scald burns. This method, with its treatment effect, is fully
comparable with others, realized at other clinical workplaces, which use
biological or other types of skin substitutes for the given indication.
Bukovčan, M.D., Ph.D.
of Burns and Reconstructive Surgery
6, 826 06 Bratislava
1. Alsbjörn B., Gilbert P., Hartmann B., Kaźmiersky M., Monstrey S., Palao R., Roberto MA., Van Trier A., Voinchet V. Guidelines for the management of partial-thickness burns in a general hospital or community setting – Recommendations of a European working party. Burns, 33, 2007, p. 155-160.
2. Atiyech BS., Hayek SN., Gunn SW. New technologies for burn wound closure and healing – Review of the literarture. Burns, 31, 2005, p. 944-956.
3. Brans TA., Hoekstra MJ., Vloemans AFPM., Kreis RW. Long-term results of treatment of scalds in children with glycerol-preserved allografts. Burns, 20, 1994, p. 10-13.
4. Brown R., Kinsty D. et al. Strategies for cell engineering in tissue repair. Wound Rep. Reg., 5, 1997, p. 212-221.
5. Brož L., Vogtová D., Königová R. Experience with banked skin in the Prague burn centre. Acta Chir. Plast., 41, 1999, p. 54-58.
6. Demling R.H., DeSanti L. Management of partial thickness facial burns (comparison of topical antibiotics and bio-engineered skin substitutes). Burns, 25, 1999, p. 256-261.
7. Ghaffari A., Kilani RT., Ghahary A. Keratinocyte-conditioned media regulate collagen expression in dermal fibroblasts. Journal of Investigative Dermatology advance online publication, 11. 9. 2008, www.jidonline.org.
8. Git M., Toda K., Grinell F. Activation of human keratinocyte migration on type 1 collagen and fibronectin. J. Cell. Sci., 96, 1990, p. 197-205.
9. Koller J., Orság M., Ondriašová E., Gräffinger I., Bukovčan P. Analysis of 1119 burn injuries treated at The Bratislava Burn Departement during a five-year period. Acta Chir. Plast., 36, 1994, p. 67-70.
10. Leicht P., Muchardt O., Jensen M., Alsbjörn BA., SŅrensen B. Allograft vs. exposure in the treatment of scalds – a randomized controlled clinical study. Burns, 15, 1989, p. 1-3.
11. Ou LF., Lee SY., Chen YC., Yang RS., Tang YW. Use of Biobrane in pediatric scald burns – experience in 106 children. Burns, 24, 1998, p. 49-53.
12. Rab M., Koller R., Ruzicka M., Burda G., Kamolz LP., Bierochs B., Meissl G., Frey M. Should dermal scald burns in children be covered with autologous skin grafts or with allogeneic cultivated keratinocytes?—“The Viennese concept”. Burns, 31, 2005, p. 578-586.
13. Singh R., Purohit S., Chacharkar MP., Bhandari PS., Bath AS. Microbiological safety and clinical efficacy of radiation sterilized amniotic membranes for treatment of second-degree burns. Burns, 33, 2007, p. 505-510.
14. Šimko Š., Koller J. Popáleniny. Martin: Osveta 1992, p. 24.
15. Tompkins RG., Burke JF. Burn wound closure using permanent skin replacement materials. World J.Surg., 16, 1992, p. 47-52.
16. Zajíček R., Brož L., Klein L., Bláha J., Königová R., Jirkovská A., Dubský M., Bureš I., Matoušková E. Xe-Derma: A new biological cover for treatment of acute and chronic wounds. Hojení ran, 2, 2008, p. 18-27.