Inclusion Criteria:  Age >18 years Women that had a laparotomy no more than 3 weeks before accrual. Surgical wound dehiscence that requires a secondary closure. Time from wound dehiscence >24 hours and <6 days. The open wound includes epidermis, dermis and sub cutaneous fat. The patient can sign an informed consent form.  Exclusion Criteria:  Patients with necrotizing fasciitis Patients with fascial dehiscence Cannot withdraw blood in the required amount (up to 18 mL per week). Known coagulation problems, abnormal thrombocytes level or if heparin is given intravenously. Subjects who are taking oral anti-coagulants or anti-agreganrts will not be excluded. Pregnancy Subject is currently receiving (i.e., within the past 30 days) or scheduled to receive systemic steroids (Prednisone- more than 10mg/d or equivalent).