DONOR SITE MORBIDITY FOLLOWING HARVEST OF SPLIT-THICKNESS SKIN GRAFTS IN SOUTH EASTERN NIGERIA

Abstract

Background

Split-thickness skin grafting is a very common procedure. Few documentation of its complications exist in the literatures especially in our sub-region where excessive scarring is a major issue.

Objective

The objective of the study was to document the common complications observed at the donor site for split thickness skin grafts.

Methods

This is a prospective study carried out at the National Orthopaedic Hospital, Enugu, Nigeria over a six month period. All patients with wounds requiring split-thickness skin grafts, who gave consent, were recruited.

An observer administered questionnaire was opened for each patient. Any donor site complication was noted on inspection and documented. Analysis of the results was done using SPSS with frequencies, mean and test of significance

Results

A total of 120 patients were recruited for the study. Males accounted for 59.2% of the patients while females made up 40.8%. Donor site complications noted were pain which was exaggerated after 24 hours, itching, infection, dyschromia, hypo-pigmentation, hyper-pigmentation, and hypertrophic scars. At 1 month post-operative period, dyschromia was the commonest complication (39.2%), followed by itching (22.5%), hypo-pigmentation (19.2%), infection (17.5%), and exaggerated pain (1.7%).

However, by 3 months, hyper-pigmentation was most common (55.4%), followed by dyschromia (37.5%), hypertrophic scar (3.6%) and itching (3.6%). Whereas by 6 months most patients had hyper-pigmentation (96.0%) while 4.0% had hypertrophic scars.

The exaggerated pain was treated successfully with analgesics and was no longer present in any patient after the first month. While infection was also treated successfully following wound swab culture and sensitivity, appropriate antibiotic therapy and local wound care. Pigmentation changes were in keeping with previous studies as hyper-pigmentation was an invariable event following healing of a partial thickness wound.

Conclusion

Donor site morbidity can be a big problem especially with regard to infection which increases duration of admission and therefore cost of management.

Introduction

Achieving skin cover is a very big task that is always required to prevent wound infection and reduce morbidity. Skin grafting is one of the earliest described surgical procedures to achieve this1-2. Often, a large surface of the body has to donate the skin for this purpose. Split-thickness skin grafting is a very common procedure and donor site morbidity can sometimes become a problem for both the patients and the care-givers. Split-thickness graft donor site is usually expected to heal like any abrasion. Patients however sometimes complain of some discomfort and discoloration that may accompany the procedure of skin grafting. Suggestions have been made that split thickness skin grafts should be taken from areas where concealment of the donor site is possible3. Not much has been done to document the morbidity associated with split thickness skin grafts in our sub-region with black population. The aim of this work is therefore to document the common complications observed at the donor site for split thickness skin grafts. The knowledge of these will help in finding means to prevent these complications as well as serving as a basis for educating patients going for the skin grafting on the probable complications since donor site morbidity, especially infection, tends to increase the cost of managing the patient. In addition, unsightly scars may constitute a cosmetic embarrassment to the patient following the harvest of split-thickness skin. Prior information about the chance for this will therefore be appropriate

Materials and Method

This is a prospective study carried out at the National Orthopaedic Hospital, Enugu, Nigeria over a six month period. All patients with wounds requiring split-thickness skin grafts consented were recruited into the study. Only patients who could have their wounds covered with split thickness skin graft from only one thigh were recruited.

History and physical examination of the patients were carried out and recipient site were prepared till they were free from B-haemolytic Streptococcus infections.

Donor site was prepared by cleaning twice with Cetrimide lotion (Savlon), dried with dry gauze and cleaned finally with Methylated Spirit before draping to expose site for surgery. Grafts were harvested using Humby knife setting thickness knob at between 0 and the first mark, which ensured harvest of thin split-thickness skin grafts and uniformity for all the patients. The total length and width of surface harvested was measured.

Occlusive three-layered dressing comprising, a non-adherent contact layer (usually gauze impregnated with petroleum jelly and antibiotics, sofratulle for this study), followed by an adsorbent layer (usually dry gauze and cotton wool) and a restrictive layer with crepe bandaging was used for dressing these donor sites.

Donor site was inspected daily for strike through of blood or serous discharge as well as evidence of infections by observing the dressings over the wounds. Additional padding was done with sterile cotton wool and crepe bandage where serous or bloody discharge was observed within 24-48 hours. Where unusual tenderness or pus discharge was observed, dressing was taken down, wound swabbed for culture and sensitivity and appropriate wound care commenced with wound dressings and antibiotics.

An observer administered questionnaire was opened for each patient. Any donor site complication was noted on inspection and documented. Patients were examined at 1, 3 and 6 months post-operatively, and were assessed for complications at donor sites after discharge. Analysis of the results was done using SPSS with frequencies, mean and test of significance.

Results

A total of 120 patients were involved in this study. There were 71 (59.2%) males and 49 (40.8%) females. The ages of the patients ranged from 1 to 81 years with a mean age of 28.1 years and a modal age group (25.0%) of 21 – 30 years. Others are as shown in figure 1.

The thigh was the donor site in all the patients with the left anterior thigh being the commonest site in 45 (37.5%) patients (figure 2).

The size of grafts used depended on the size of wound to be covered. For convenience, they were categorised into three groups namely: Small sized grafts – for all total graft dimensions less than (<) 10cm x 5cm, medium sized grafts – for all total graft dimensions ranging from 10cm x 5cm - 20cm x 10cm and large sized grafts – for all total graft dimensions greater than (>) 20cm x 10cm.

The commonest size used during the study was the medium sized grafts with 52.5%, followed by large sized grafts, 28.3% and lastly, the small sized grafts with 19.2% of the grafts. However, there was no particular pattern of variation or distribution of complications observed with the size variations.

Complications observed in the first month following the surgery include dyschromia (a combination of hypo-pigmentation and hyper-pigmentation) (39.2%), infection, (17.5%), itching, (22.5%), (Table 1).

By 3 months post-operative period, hyper-pigmentation was the most commonly observed complication in 55.4%, (Table 2). This usually presented an unsightly appearance especially in fair complexioned individuals. This could raise a lot of concern in such patients and patients going for skin grafts should be informed of this possibility and surgeon should ensure this is understood by them.

At six months, it was observed that most (96.0%) of the patients had hyper-pigmentation, 4.0% had hypertrophic scars while 19, (15.8%) did not report for follow up. The result also revealed that there was no statistical significance between the size of donor site defects and the complications at p<0.005.

Dyschromia, the commonest complication observed in 47 (39.2%) of the patients at 1 month, reduced to 42 (35.0%) by three months and had disappeared completely at 6 months in all the patients. Hyper -pigmentation however increased with time after skin was harvested from the thigh from zero in the first month, to 62 (51.7%) at the end of the third month and 97 (80.8%) by 6 months. Hypo-pigmentation was also observed only at the end of 1month in 23 (19.2%) patients and disappeared subsequently

It was further revealed that most of the complications reduced with time. Hence pain, present in only two of the patients, had disappeared before the 3months assessment. Itching was observed in 27 (22.5%) of the patients in the first month of the donor site wound. It however had drastically reduced to 4(14.8%) of the total number of patients with itching by 3 months, (Table 3). This is statistically significant (at P<0.0001).

Infection was only observed within the first month in 21 (17.5%) and had disappeared completely by three months post-operatively. Staphylococcus aureus was the most common organism identified as a cause of donor site infection in (61.9%), followed by Pseudomonas sp. (28.6%) while the infecting organisms in the remaining 9.5% were E. coli.

Discussion

DISCUSSION

Skin grafting remains a utilitarian means of achieving soft tissue reconstruction, 4 even in the age of micro-surgery and free-tissue transfer. Since Reverdin5 got credit worldwide for his report on pinch grafts in 18696 and Pollock7 applied the first successful autograft to a burn wound, the use of skin grafts have been popular among Plastic and other surgeons.

Superficial partial-thickness wounds, like donor site wounds, affect the epidermis and superficial parts of the dermis. Such wounds heal by epithelialization from the margins of the wound, where basal keratinocytes change into a proliferating migratory cell type and cover the damaged area. Each hair follicle and sweat gland is lined with epithelial cells capable of contributing to epithelial regeneration across the wounded surface8. Unlike superficial partial thickness, deep partial-thickness injuries however involve greater dermal damage that results in fewer skin appendages remaining and therefore they take longer to heal while full-thickness injuries are characterized by the complete destruction of epithelial-regenerative elements. Epithelialization occurs from only the edge of the full thickness wound, hence the wounds heal by contraction leading to cosmetic and functional defects.

Donor site problems, including exaggerated pain, and often bad scars, when infected especially in Blacks, have constituted a major challenge to the use of this important method of wound cover. Increased cost of treatment is also a concern to the patient especially when plans are not made for a probable infection that may necessitate additional costs to the payment made by patients in an environment like ours where the health insurance has not been properly established. Documentation of donor site complications following harvest of skin grafts, especially among blacks who tend to form bad scars more commonly, is therefore important in our sub-region. This will also allow proper education of patients as to probable complications following skin grafting surgery. The current study revealed pigmentation problems; either hyper-pigmentation or hypo-pigmentation in donor sites.

The pigmentation changes appeared to be a spectrum, with hypo-pigmentation observed initially following re-epithelialization, and increasing pigmentation resulting in dyschromia (hyper-pigmentation interspersed with hypo-pigmented patches) and most eventually becoming hyper-pigmented by 6 months post- surgery. In fully healed partial- and full-thickness burn scars, it has been observed that the epidermis showed melanocyte counts which were always above normal, and particularly so at 6 weeks post-burn and beyond. This increase in melanin correlated closely with naked eye observations of hyper-pigmentation.8 Pepper9 and Snell10 (in the guinea-pig), and Breathnach11 (in man), showed an initial decrease in number of melanocytes and in melanin in partial thickness wounds in the first 6-7 weeks post-burns or post-excision. This was followed by an eventual increase in number of melanocytes and in melanin in the healing wound, an increase which was noted to have coincided with naked eye observation of hyper-pigmentation. It can therefore be inferred that following partial thickness injury or excision and hence following split-thickness skin grafting, dyschromia and hyper-pigmentation will invariably occur with healing especially in the black population.

It has also been previously reported that, after taking grafts at .012" to .020', hypertrophic scarring, and pigmentation changes are not uncommon in donor sites, especially in children and patients with considerable skin pigmentation, such as Blacks, Hispanics, and Orientals12. While the infection rate was 17.5%, which were promptly treated, only 3.3% of the patients had hypertrophic scarring from the wounds observed at three months with no increase in the number even at six months. All the cases of infection were local infections which did not involve the whole surfaces of the donor sites and they all responded well to combined use of both topical and/or systemic antibiotics alongside local wound care.

Donor site scarring has been observed to be proportional to donor thickness and to donor site infection; the deeper the donor site, the longer it takes the donor site to heal and the greater the risk of infection12. The donor sites in this study were approximately the same thickness. The scarring observed may be due to infection which possibly caused the deepening of the wounds. Excessive scarring in the blacks have however long been known13-16. Itching in healing wounds is a common symptom and has been adduced to the growth of free nerve endings. With a partial thickness wound like the donor site, the nerve endings are exposed and sprouting new nerve endings also contribute to the itching observed. Where the donor site is extensive as with some of the patients in this study, the itching is pronounced and could be unbearable. Use of anti-pruritic agents may be of help to the patients.

In conclusion, donor site morbidity is real and hyperpigmentation, itching, infections and scarring are major complications to donor sites of split-thickness skin graft among the black populace. Patients should therefore be educated and informed about the possibility and their chance of developing these complications when scheduled for split-thickness skin graft. While patients in this study were only followed up for a period of six months, it would be necessary for future studies to look at the long term complications of the donor sites.