IRCT2016020418842N11 IRCT 2016-03-16 Vice chancellor for research,Tehran University of Medical Sciences. The effectiveness of PRP Gel in wound healing caused by resection of Pilonidal sinus Comparative study on potential of platelet-rich plasma Gel and regular dressing in duration of wound healing in patients who underwent pilonidal sinus surgery 2012-09-22 anticipated 123 Complete https://irct.ir/trial/16975 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Supportive. 3 Pilonidal Sinus Disease with abscess. Intervention 1: In intervention group,the obtained PRP was additionally injected into the depth (13mm) of the wound. It was also applied to center of each circle (0.1cc) and wound site (1 cm in diameter) through injection. The injection was preformed right after surgery and then weekly. Then the PRP Gel (activated by CaCl2) was added 2ml/cm3 of wound volume and the casual dressing performed. Washing the wound with normal saline (0.9%) twice a day was ordered. Wound debridement was also performed to remove the necrotic tissues if necessary. Intervention 2: Classical dressing (sterile absorbent cotton gauze) was applied for the control group. Washing the wound with normal saline (0.9%) twice a day was ordered. Wound debridement was also done in order to remove the necrotic tissues whenever necessary.