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Collagen Dressing in The Management
of Donor Site of Split Thickness Skin Grafts
P Halankar*, D Cunha-Gomes**, C Chaudhari**
Collagen sheets were used as a donor
site dressing material in a group of thirty patients. The rate
of epithelialisation was similar to other dressing materials
in routine use. In the group, pain or discomfort experienced
and the convenience of the dressing in clinical use was assessed.
The absence of donor site pain and a decreased analgesic requirement
in patients was considered the greatest benefit.
Inspite of newer advances split thickness skin grafts
(STSG) still have an important place in many areas of
plastic surgery. Though the technique of skin grafting
is more or less standardized the treatment of the donor
site differs greatly and has been a topic of debate. The
STSG donor site usually receives little attention and
is often a source of delayed healing with considerable
pain and discomfort to the patient. Thus it is not uncommon
for patients to complain more about the pain at the donor
site than at the site of surgery. To overcome this various
dressing materials have been used.
Skin is natural barrier that prevents penetration of
pathogens and escape of interstitial fluid. The harvest
of a split thickness skin graft causes a partial thickness
injury and an outflow of blood and protein rich exudate
from the wound. This exudate and coagulated blood combine
to form an eschar which provides a temporary cover to
the wound and underlying regenerating epithelium. However
the eschar does not prevent tissue desiccation and infection
at the donor site which can thus convert a partial thickness
injury to a full thickness loss.1 After the harvest of
STSG, the new epidermis arises from proliferation of the
remaining epithelial cell layer at the donor site periphery
and reserve cells in the remaining hair follicles, sebaceous
glands and sweat glands. This is the first phase in the
healing of a donor site. The process of cell proliferation
is followed by migration of the cells outward until the
wound is reepithelialised.2 Complete re-epithelialisation
occurs in 10-14 days, although the rate may be affected
by the local wound environment.3
Split thickness skin graft donor sites have been treated
with open or closed dressings.5 The open technique of
donor dressing has been long abandoned in favour of the
closed method since occlusive dressings have shown better
results with shorter healing time, superior quality of
the regenerated epithelium and more patient comfort. It
has also shown the added advantage of protecting the donor
site from desiccation, mechanical trauma and contamination.5
A more traditional method is dressing the donor site with
a fine mesh gauze beneath a closed absorbent dressing.
The gauze may be dry but is usually impregnated with bismuth,
scarlet red or petroleum jelly. Though the gauze initially
provides a moist environment it gradually becomes desiccated
and an eschar forms which acts as a mechanical barrier
and impairs cellular migration. However these dressings
can also become permeable to bacteria if wound exudate
soaks through the entire thickness of the dressing. Furthermore
movement of the donor site dressing produces shearing
forces that may cause pain, dislodge the dressing and
impair the migration of epithelial cells. At the time
of removal, the dressing is adherent and liable to damage
the fragile regrown epithelium.1,6
Studies have shown that a moist environment promotes
healing in a partial thickness skin loss. The use of polyurethane
film, a semi permeable dressing maintains a moist environment
allowing diffusion of oxygen and water vapour while providing
a barrier to the passage of wound exudates. It has claimed
to reduce the healing time and donor site pain. However
it has proved difficult to use as wound exudate collects
beneath the film and is liable to leak out.1,6 Other experiments
have used silicon gel sheets, also a semi permeable dressing
with similar results.
During the last decade newer dressing materials have
been developed which interact with the wound exudate to
form a moist non adherent gel. Commonly used dressings
are calcium alginate and bilaminate hydrocolloid membranes.
They both have been reported to accelerate healing at
the donor site. However the main drawback of both dressings
is the time required to apply the dressing. The hydrocolloid
dressing has the added disadvantage of leakage of wound
exudate which requires redressing.6
Recent experiments have shown that biological dressings
create the most physiological interface between the wound
surface and the environment and permit the body’s
reparative and immune system to function most efficiently.
These dressings are natural, non immunogenic, non pyrogenic
and hypo allergenic. Experiments have been carried out
using porcine xenografts, amniotic membranes and collagen
sheets. However both have shown poor results. Porcine
xenografts showed a large percentage of abnormal healing
due to sub epithelial incorporation and rejection and
the amniotic membrane dressings showed a delayed healing.3,4
We have used collagen sheets as a donor site dressing
which comes close to being called an ideal donor site
dressing. We hereby present our experience with the same.
|Material and Methods
A group of 30 patients were included in this study
with 21 males and 9 females ranging from age 18 to 72
years. All patients required split thickness skin grafts
of approximately 100-250 cm2 in area to provide cover
for various indications. All grafts were taken from the
anterior and medial aspect of the thigh. The donor site
of patients was prepared for five minutes with povidone
iodine scrub and draped with sterile sheets. The skin
and knife blade were lubricated with sterile liquid paraffin.
Split thickness skin grafts were harvested with a Humby’s
knife, following which pressure was applied to the donor
site with saline soaked gauze pieces to achieve haemostasis.
A collagen sheet of the required dimension was selected
and washed in normal saline to remove the preserving medium.
It was then applied to the donor site while ensuring that
all the entrapped air was removed. Oozing of blood immediately
after application was seen, but the blood was easily removed
by cautious pressure over the sheet. A light dressing
was given over a non-adherent padding.
In the immediate post-operative period the patient was
asked to assess the pain or discomfort caused by touch
or pressure on the donor site. Pain being a subjective
assessment was graded as none, mild, moderate or severe.
In the later post operative period pain felt on walking
was similarly assessed and the requirement of analgesics
for donor site pain was evaluated in both cases.
The donor site dressing was inspected daily for soakage of blood and exudate. If the dressing was soaked, painful or foul smelling, it was opened to look for infection, haematomas or an allergic reaction to the collagen. In these patients a redressing was done using a framycetin impregnated paraffin gauze. In the remaining patients, the dressing was opened directly on the fourteenth day and donor site re-epithelialisation scored as 100% healed, 90-100% healed and < 90% healed. At the same time the ease of removal of dressing and associated pain at the time of removal was noted.
The patients on follow up were inspected for hypertrophic scarring of the donor site area.
The dressing was thus assessed based on the following criteria - healing at 14 days, infection, and donor site pain.
|Fig. 1 : Sterile collagen dressing.
All 30 patients were followed upto complete healing
of the donor site. In the group all patients tolerated
the collagen dressing well and there was no allergic reaction.
In the early postoperative period on assessment of donor
site pain to touch and pressure, 2 patients in the group
had no pain, 23 rated the pain as minimal while 7 patients
assessed the pain as moderate and tolerable. There was
no complaint of severe pain and none of the patients required
additional analgesics for donor site pain. Once the patients
were mobilized by the third postoperative day they were
assessed again for pain while walking. In the patient
group 21 patients assessed the pain as minimal, 7 assessed
the pain as moderate and 2 as severe. The 2 patients who
had severe pain on walking also had severe pain on touch
and pressure and required additional analgesics to relieve
them of the donor site pain. All other patients had no
analgesic requirement for the donor site.
All donor site dressings in the study group were inspected
daily. In 2 patients soakage of wound exudate was seen
on the fifth and eighth post operative day respectively.
These were the two patients in whom there was significant
donor site pain. In both patients the donor site dressing
was foul smelling and the wound was covered with purulent
discharge with degradation of the collagen sheet. The
infection was limited to the donor site with no evidence
of cellulitis of the surrounding skin or fever. The infected
sites were redressed with framycetin impregnated paraffin
gauze. In both patients the wounds were redressed after
forty-eight hours by which time pain had subsided.
|Fig. 2 : Donor site of a patient covered with a collagen dressing.
||Fig. 3 : Healed donor site.
On the fourteenth post operative day the donor site dressings
were soaked in saline and easily removed with no pain
in 5 patients, while 18 and 7 patients had minimal and
moderate pain respectively. None of them complained of
severe pain. In the group 24 patients showed 100% reepithelialisation,
4 showed between 90-100%, while the two with infected
donor sites had < 90% reepithelialisation. In the group
1 patient had a haematoma beneath the collagen dressing
but there was complete re-epithelialisation beneath the
haematoma. On late follow up of 26 patients, 2 showed
hypertrophic scarring of the donor site.
Collagen dressings used are composed of type 1 and
type 3 bovine collagen which is similar to human collagen
and thus prevents rejection. It is commercially available
in a sterile pack and is thus easy to use.
Collagen as a donor site dressing has shown that the
time to complete reepithelialisation is comparable with
other dressing materials. However it is not possible to
assess the true wound healing as the wound cannot be kept
under continuous observation and the mean time to the
first dressing may be longer. Thus many of the donor sites
may have healed long before they are first inspected.
Patients with collagen dressings are found to have only
minimal to moderate pain in the entire post operative
period and during the first dressing. In these patients
analgesic requirement is reduced and early mobilisation
can be done. Thus the major advantage of using collagen
as a donor site dressing is decreased pain.
The collagen sheet once adherent to the wound has low
friction between the wound surface and dressing and this
has made it suitable for awkwardly sited donor sites.
Also once applied it does not require a bulky dressing
which would hamper mobilisation, or require a change of
dressing as there is no soakage of the dressing due to
The collagen provides a scaffolding for epithelial regrowth
and prevents exudation from the raw area.7,8 After 48
hours the film is transformed into a stiff sheet which
is stable enough to withstand pressure and shearing of
clothes. Thus it protects the donor site from mechanical
trauma and infection. When reepithelialisation is completed
the overlying film and coagulated blood separates spontaneously.
Thus removal of the dressing is easy and pain free.
Disadvantages seen with the use of a collagen dressing
is the formation of an haematoma in cases where meticulous
haemostasis has not been achieved. Also infection at the
donor site causes a complete degradation of the film and
is associated with significant donor site pain. Thus donor
site pain in patients where collagen dressing is used
is highly suggestive of wound infection.4,9 The wound
infection is usually limited to the donor area with no
associated systemic infection, and it does not convert
the donor site to a full thickness loss and once the wound
is redressed it does not affect the time of reepithelialisation.4
Thus collagen dressings appear to have a great advantage
over other dressing materials for donor sites especially
in terms of a pain free donor site and thus early mobilisation
of the patient and a decreased morbidity. With its ease
of application, with no need for redressing, a pain free
donor site reepithelialisation in the accepted time it
attempts to fulfil the criteria of an ideal donor site
However this is only a preliminary study and further
evaluation of pain using various pain scales and comparative
studies with other dressings will be required before its
advantage can be confirmed.
||Weber RS, Hankins P, Limitone E, et
al. Split-Thickness Skin Graft Donor Site Management.
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gauze Dressing. Arch Otolaryngol Head Neck Surg 1995;
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||Freshwater MF, Chi Tsung Su, Hoopes
JE. A Comparison of Polyurethane Foam Dressing and
Fine Mesh Gauze in The Healing of Donor Sites. Plastic
and Reconstructive Surgery 1976.
||Salisbury RE, Wilmore DW, Silverstein
P, Pruitt BA. Biological Dressing for Skin Graft Donor
Sites. Arch Surg 1973; 106 : 705-6.
|| Ponten B, Nordgaard JO. The Use of
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RE, Baran C. Which dressing for split thickness skin
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||Porter JM. A comparative
investigation of Re epithelialisation of split skin
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and alginate dressings. British J Plastic Surgery
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||Gupta RL, Jain RK, Kumar M, et al.
Fate of Collagen Sheet cover for artificially created
raw areas (an experimental study). Indian J Surgery
1978; 40 (12) : 641-45.
||Gupta RL, Jain RK, Kumar M, et al.
Role of collagen sheet cover in Burns. (A Clinical
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||Horch RE, Stark GB. Comparison of the
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*Registrar; **Consultant Plastic Surgeon, Bombay Hospital and Medical Research Centre,
New Marine Lines, Mumbai 400 020.