INTRODUCTION & REVIEW OF LITERATURE

 

Split thickness skin grafting is a common reconstructive technique for the treatment of patients with deep burns and other traumatic injuries^1.

Various types of dressing materials are available for the management of donor site after harvesting a split thickness skin graft such as semi permeable film dressings, semi permeable foam dressings, hydrogels, hydrocolloids, alginate dressings, bioactive wound dressings such as collagen, hyaluronic acid, chitosan and elastin or tissue engineered medicated and composite dressings².

Selection of an ideal dressing in such vast variety is a challenge. Thus, this study is aimed at the most common presentation of the patient that is pain at the donor site of split thickness skin graft, as primary outcome and similarly surgical site infection, time of epithelialization and scar as secondary outcomes.

 

Paraffin gauze is a sterile, occlusive dressing consisting of fine mesh; absorbent gauze impregnated with approximately three times its weight of white petroleum³. It remains moist to minimize drying out and adherence. Non-adherent fine mesh reduces pain and trauma during dressing changes. It conforms to body contours to help seal air leaks and unwanted fluid loss. It is non-toxic, non-sensitizing, and non-irritating⁴.

 

Collagen sheet is a biological dressing derived from bovine source, comprising mostly type I and type III collagen that is retained in the tissue and gradually absorbed .They have following properties:

 1. Biological

Collagen sheet is non-inflammatory, non-toxic, has low antigenicity and minimal biodegradation. It facilitates migration of fibro-blasts and microvascular cells and helps in the synthesis of neo-dermal collagen matrices. It has further following characteristics:

2. Physiological

Collagen sheet is elastic, soft, and supple, has good tear strength and modulates fluid flux from the wound. It is impermeable to bacterial migration and has good suturing characteristics^5.

           

SPLIT THICKNESS SKIN GRAFT

 

A skin graft is a segment of dermis and epidermis that is separated from its blood supply and donor site and transplanted to another recipient site on the body ⁶. It is classified as autograft, allograft, homograft or heterograft.

Partial thickness skin grafts consist of the epidermis and a portion of dermis and are called split thickness skin grafts (STSGs). Full thickness skin grafts (FTSGs) include the epidermis and entire dermis, with portions of the sweat glands, sebaceous glands and hair follicles⁷. The STSG is harvested with a dermatome which is an air or electric powered instrument that can be adjusted for width and depth to cut uniformly thick grafts usually in strips of 0.006 to 0.024 inches in thickness⁸. The STSG can be meshed by cutting slits into the sheet of graft and expanding it usually in a 1:1.5 or 1:2 ratio. An STSG can be taken from anywhere in the body; donor site considerations include color, texture, thickness, amount of skin required and scar visibility⁹.

 

The donor site wound is often painful and if the dressing does not contain wound exudate, it is prone to infection¹⁰. An ideal dressing maintain a moist environment and support rapid healing without adhering to the wound bed. It needs to be absorbent and easy to apply and remove¹¹.   

P Halankar et al, studied Collagen Dressing in The Management of Donor Site of Split skin thickness skin grafts in April 2005 with 30 patients and concluded that collagen sheet caused less pain in donor site compared to other dressing materials however the healing time was unaffected¹².

Fernandes de Carvalho V et all in 2011 carried out a Clinical trial comparing 3 different wound dressings for the management of partial-thickness skin graft donor sites. They recruited 34 burn patients and compared bovine collagen calcium-alginate dressing covered with transparent polyurethane film , only transparent polyurethane film dressing and rayon soaked in 0.9% saline when used in donor site. Study findings suggested that use of a collagen calcium-alginate dressing with a transparent film covering reduces the time for complete epithelialization and may reduce pain related to skin graft donor sites¹³.

Another study conducted in 2015 by Narayanathuet al compared collagen and paraffin gauze, and found that Bovine type 1 collagen reduces pain and soaking at skin graft donor site. The reduction in pain is highest for first 3 days and then gradually diminishes. However there was minimal effect of collagen on the rate of epithelization¹⁴.

In a retrospective study in 2021, by Dave TJ et al  there was  significant difference  in median pain score between two groups on POD 3, POD 7 and  POD  10.  Pain  score  was  low  in  collagen  group compared  to  conventional  group  at  all  the  intervals. Similarly  there  was  significant  difference  in  median Vancouver scar  score between two groups  on POD 10, POD 14 and POD 21. Vancouver scar score was  low in collagen group compared to conventional group at all the intervals.  In the  collagen  group 6.7%  had  surgical  site infection and in conventional group 13.3%  had surgical site infection¹⁵.

 

Similarly in the study by Ayaz et al, significant reduction in pain and pruritus in patients with collagen dressing was noted on POD 1 and POD 14 respectively. Considerable reduction in use of analgesics especially opioids observed with collagen dressing and also reduction in the duration of use of analgesics was observed with collagen dressing^16.

 

Similarly in the study by Sreekumar et al the pain was less in the collagen area when compared to the paraffin gauze area. The difference was highest for the first 3 days (2.16 versus  5.86,  p<0.01)  reduced for  the  next  4  days (0.4 versus 3.4, p<0.01) and was minimal for the last 3 days (0 versus 1, p>0.02)¹⁷

Meta-analysis and Systematic Review of Skin Graft Donor-site Dressings with Future Guidelines was performed by Serebrakian AT in 2018. A comprehensive systematic review was conducted across PubMed/MEDLINE, EMBASE, and Cochrane Library databases to search for comparative studies evaluating different STSG donor-site dressings in adult subjects published between 2008 and 2017. It was concluded that the literature on STSG donor-site dressings has not yet identified an ideal dressing. Although moist dressings provide superior outcomes with regard to pain control and wound healing, there continues to be a lack of standardization^18.

 

Visual Analog Pain Score

 The visual analog scale (VAS) is a pain rating scale^, first used by Hayes and Patterson in 1921. Scores are based on self-reported measures of symptoms that are recorded with a single handwritten mark placed at one point along the length of a 10-cm line that represents a continuum between the two ends of the scale—“no pain” on the left end (0 cm) of the scale and the “worst pain” on the right end of the scale (10 cm). Measurements from the starting point (left end) of the scale to the patients’ marks are recorded in centimeters and are interpreted as their pain¹⁹.

 

Vancouver Scar Scale

 

The first concepts of scar assessment scales were reported in the late 1980s, but the first widely used, validated scar scale was developed in 1990 by Sullivan et al., which became widely known as the Vancouver Scar Scale (VSS) [19]. The VSS consists of four items: vascularity, pigmentation, thickness, and pliability. Since this first introduction to scar assessment scales, the development of many other scales followed²⁰.

Vancouver Scar Scale

AIM AND OBJECTIVES

 

AIM: To compare the efficacy of collagen sheet dressing with conventional dressing for donor site management in cases of split thickness skin graft.

 

OBJECTIVES:

 

Primary Objective:

To compare the efficacy of collagen sheet dressing with conventional dressing in assessing pain in split thickness skin graft donor site based on Visual analog scale (VAS) [18] on days 01, 07, 14 and 21.

 

Secondary Objective:

1. To compare the days required for complete epithelialization assessed by the day on which

    dressing falls off on it’s own.

2. To compare the soakage and requirement of secondary dressing.

3. To compare the ultimate scar formation at donor site at 3^rd and 6^th month.

 

 

 

 

MATERIALS AND METHODS

 

 

1. PLACE OF STUDY:

Pt B.D. Sharma Postgraduate Institute of Medical Sciences, Rohtak, Haryana

 

2. DURATION OF STUDY:

18 months (October 2024 to March 2026)

 

3. STUDY POPULATION:

Patients undergoing split thickness skin graft for any indication.

 

4. SAMPLE SIZE CALCULATION:

To test for

          H0: µ1 = µ 2  

          H1: µ1  Âµ 2

Where µ1 and µ2 are means of Numerical pain rating scale value in control and study arms respectively

          With:

      Âµ 1 =2.90 with SD1= 1.41

      Âµ 2 = 0.45 with SD2=0.82

      Î± = 5% and power = 80%

 

The minimum required sample size is 04 in each arm (total 08) however, we will study 25 patients

in control Arm and 25 patients in study arm (total 50 patients).

 

5. INCLUSION CRITERIA

1. Age: 20-40 years of age         

2. Sex: Both males and females

 

6. EXCLUSION CRITERIA

      1. Immunocompromised patients under cytotoxic drugs or steroids

      2. Any scar at donor site

 

7. SUBJECT WITHDRAWAL CRITERIA: Subjects are free to withdraw consent to participate at any point during the duration of study.

 

8. STUDY PROTOCOL:

1.  All cases undergoing split thickness skin graft at this tertiary care hospital will be considered.

2.  Thickness of graft will be kept same in all patients i.e. 0.3-0.45mm.

3. As per existing protocols, surgery will be performed and post operatively managed with standard dressing and care.

4. Allotment of patients into Group A (Conventional dressing group) and Group B ( Collagen sheet group) will be done based on simple randomization by lottery method.

5. Significance of the study will be explained and an informed written consent for participation in the study will be taken at the time of admission in the hospital / after surgical procedure is completed.

6. Performa for collection of data including personal particulars, history & other relevant variables will be filled.

7. Pain score will be calculated on specified days of the study as per Visual analog scale (VAS).

8. Days to complete epithelialization shall be noted once dressing falls on its own.

9. Soakage of dressing will be measured. It will be considered mild if it involves only one part of thigh i.e., anterior/posterior/lateral/medial, Moderate if it involves more than one aspect and severe if circumferential soakage is present.

10. Scar assessment will be done as per Vancouver scale.

 

9. Statistical analysis: All data will be tabulated and appropriate statistical tests will be used to compile the results. Data collected will be categorized and coded as appropriate. The data will be compiled, tabulated, and analyzed using SPSS 22.0 software. Regression analysis and the Chi-square test will be applied for analysis wherever applicable. The confidentiality of the data of the study subject would be ensured.

 

Ethical considerations: Written informed Consent of the participants and Instituitional Ethical committee clearance will be taken.

 

FLOWCHART FOR THE STUDY

 

 

 

PROFORMA

 

1	DATE OF ADMISSION:			DATE OF DISCHARGE:
	Name -			Age-                years				Sex- Male/Female
	CR Number-
	Contact Number-			Date of Surgery
2	Diagnosis
3	Comorbidities
4	General Physical Examination		Pulse			Blood Pressure				Resp Rate
5	Local Examination
6	Intra-Operative Finding
7	Pain Score ( VAS)		Day 01		Day 07		Day 14				Day 21
8	Days to complete epithelialization
9     10	Soakage     Vancouver Scar scale		Mild
			Moderate
			Severe
			3rd month				6th month