Effect of Autologous Fat Grafts in Management of Hypertrophic Scars at Kenyatta National Hospital

Abstract

Background: Hypertrophic scars are a common global health problem with significant effects on overall quality of life and a huge burden on health care systems. There are numerous treatment modalities for hypertrophic scarring described in literature to date, with silicone gel being the most preferred, however Autologous fat graft (AFGs , henceforth) have also been suggested as an alternative due to their being readily available and cheaper. Despite its possible use in regenerative medicine, few studies have been done to elucidate its effectiveness in treatment of hypertrophic scars. Study objective: This study therefore evaluated the effectiveness of AFGs in the management of hypertrophic scars. Study design: Quasi experimental one group pre-test-post - test (non RCT) study design Setting: Kenyatta National Hospital Ethical consideration: All data was collected after approval was sought from and granted by the Kenyatta National Hospital / University of Nairobi Ethics Review Committee (KNH/UoN ERC). Informed consent was sought from all the participants. Methodology: One group of fourty nine (49) adult consenting participants, presenting with hypertrophic scars were recruited. Prior to the administration of the intervention, patient demographic data was collected following which punch biopsies of their wounds were taken for histology. Pain scores were recorded. AFGs were then injected into the hypertrophic scars of the same patients at a dose of 1ml/3.5cm2 scar area. Scar assessment by a blinded research assistant was done at day 0 and 28. This assessment was guided by the POSAS scale. A punch biopsy was

then collected for histology on day 0 and 28. A structured questionnaire was used to collect the data. Data management: SPSS (IBM version 21) was used to analyse the data. Tables, graphs and digital photography was used to present the results obtained in the study. The measurements obtained were fed in SPSS from where mean percentages (of the surface area of the scar, vascularity and hyperpigmentation), means (of pain and itchiness scores, height of the scar and pliability scores) and standard deviations were calculated. Age differences were assessed using ANOVA, gender differences as well as group differences using students’s ’t - test, correlations by cross-tabulations and pearsons correlational test. A p value ≤ 0.05 was considered significant at 95% confidence interval. The findings were represented in tables, line graphs and photomacrographs. Results: The average age of the participants was 26.20 (18-32) years with the majority being female (76%) as compared to male (24%). In both gender, burns (72%), were the most common causes of scars and in terms of age, the mean age of the scar was >1 year with no gender (p value = 0.907) or age differences (p value = 0.907). The most common scar site was the forearm (16%) and the thigh (16%). The mean surface area of the scar was 39.96% (7 - 100). There were statistical significant differences between the patients’ scores before and after intervention specifically on pain, itch and characteristics of the scar (color, stiffness, thickness and regularity). There were also statistical significant differences between the observers’ scores before and after intervention on vascularity, pigmentation, thickness, pliability, surface area and overall opinion of the scar (p value = 0.000).

Conclusion: Findings of our study support that AFGs may be beneficial in the treatment of hypertrophic scars as shown by the improvement of both observer’s and patient’s scores preintervention and post-intervention. Our findings are consistent with existing literature.