Abstract: Objective To explore the clinical effects of concentrated growth factor (CGF) combined with plasma albumin gel (PAG) in treating facial depressed scar. Methods From January 2018 to June 2019, 14 patients in the First Affiliated Hospital of Zhengzhou University and 10 patients in Henan NO.3 Provincial People′s Hospital with facial depressed scar who met the inclusion criteria were admitted, and their clinical data were retrospectively analyzed by the method of case-control study. Based on the method of treatment, 8 patients (4 males and 4 females) aged 28.50 (25.50, 31.50) years were enrolled in CGF alone group, 8 patients (3 males and 5 females) aged 32.00 (28.50, 35.00) years were enrolled in PAG alone group, and 8 patients (5 males and 3 females) aged 33.50 (29.00, 35.75) years were enrolled in CGF+ PAG group. Suitable amount of CGF, PAG, and CGF+ PAG (mixed at a ratio of 1.0∶1.0-1.0∶1.5) prepared from autologous blood were injected subcutaneously via a single or multiple entrance (s) into the depressed scar of patients in CGF alone, PAG alone, and CGF+ PAG groups respectively to fill up the concavity, once every 4 weeks for a total of 3 times. Before the first treatment (hereinafter referred to as before treatment) and 3 months after the last treatment (hereinafter referred to as after treatment), the Goodman & Baron Acne Scar Grading System was used for scar grading, and the difference was calculated; the Anxiety Self-Rating Scale was used to score anxiety, and the difference was calculated. The Visual Analogue Score was used to score pain immediately after the first treatment. By one, two, and three months after treatment, the patients′ satisfaction to scar treatment was scored, and the Global Aesthetic Improvement Scale was used to score the scar improvement. Adverse reaction of patients after treatment was monitored. Data were statistically analyzed with Fisher′s exact probability test, Kruskal-Wallis H test, Mann-Whitney U test, Bonferroni correction, and Wilcoxon signed rank sum test. Results (1) The scars of patients in the three groups were all graded 4.00 (4.00, 4.00) before treatment (χ²<0.001, P>0.05). By three months after treatment, compared with 2.00 (1.25, 2.00) of CGF alone group, the scar grades of patients in PAG alone group and CGF+ PAG group (3.00 (2.00, 3.00) and 1.00 (1.00, 1.00), respectively) had no significant change (Z=2.199, 2.003, P>0.05). The scar grade of patients in CGF+ PAG group was significantly lower than that in PAG alone group (Z=3.229, P<0.01). Compared with those before treatment, the scar grades of patients in CGF alone group, PAG alone group, and CGF+ PAG group were significantly reduced three months after treatment (Z=2.588, 2.598, 2.640, P<0.05 or P<0.01). The difference in scar grade before and after the treatment was significantly higher in CGF+ PAG group than in PAG alone group (Z=3.229, P<0.01). (2) The anxiety scores of patients in the three groups were similar before treatment and 3 months after (χ²=2.551, 2.768, P>0.05). Compared with those before treatment, the anxiety scores of patients in CGF alone group, PAG alone group, and CGF+ PAG group were significantly reduced three months after treatment (Z=2.395, 2.527, 2.533, P<0.05). The differences in anxiety score before and after the treatment were similar among the three groups (χ²=1.796, P>0.05). (3) The pain scores of patients in the three groups were similar immediately after the first treatment (χ²=0.400, P>0.05). (4) By one and two month (s) after treatment, the patients′ satisfaction scores to scar treatment in the three groups were similar (χ²=2.688, 5.989, P>0.05). By three months after treatment, the patients′ satisfaction score to scar treatment in CGF+ PAG group was significantly higher than that in PAG alone group (Z=2.922, P<0.01). Compared with those one month after treatment within the same group, the patients′ satisfaction scores to scar treatment in CGF alone group, PAG alone group, and CGF+ PAG group were significantly increased two and three months after treatment (Z=1.121, 2.392, 2.000, 2.828, 2.449, 2.598, P<0.05 or P<0.01). Compared with those two months after treatment within the same group, the patients′ satisfaction scores to scar treatment in CGF alone group, PAG alone group, and CGF+ PAG group were significantly increased three months after treatment (Z=2.271, 2.000, 2.646, P<0.05 or P<0.01). (5) One month after treatment, the scar improvement scores of patients in the three groups were similar (χ²=4.438, P>0.05). Two months after treatment, the scar improvement scores of patients in CGF alone group and CGF+ PAG group were 2.00 (2.00, 2.75) and 2.00 (2.00, 2.00) points, respectively, which were significantly higher than 1.00 (1.00, 1.00) point of PAG alone group (Z=3.303, 3.771, P<0.01). Three months after treatment, the scar improvement score of patients in CGF+ PAG group was 3.00 (3.00, 3.00) points, which was significantly higher than 2.00 (2.00, 2.75) points of CGF alone group and 1.00 (1.00, 2.00) points of PAG alone group (Z=2.450, 3.427, P<0.05 or P<0.01). Compared with those one month after treatment within the same group, the scar improvement scores of patients were significantly higher in CGF alone group and CGF+ PAG group two and three months after treatment and in PAG alone group three months after treatment (Z=2.828, 2.828, 2.530, 2.640, 2.121, P<0.05 or P<0.01). Compared with that two months after treatment within the same group, the scar improvement score of patients in CGF+ PAG group was significantly higher three months after treatment (Z=2.449, P<0.05). (6) After injection, all patients in the three groups had slight redness and swelling at the needle prick point and no other adverse reactions. Conclusions CGF combined with PAG can reduce the scar grading, anxiety of patients, and enhance patients′ satisfaction and scar improvement in the treatment of patients with facial depressed scar. The combined CGF+ PAG injection, without significant adverse reactions, is better than single component injection and is worthy of clinical application.