Abdominal Injuries/classification; Trauma Severity Indices; Wounds, Penetrating/classification; Abdominal Injuries/complications; Abdominal Injuries/surgery; Adolescent; Age Factors; Analysis of Variance; Blast Injuries/classification; Blast Injuries/complications; Blast Injuries/surgery; Child; Child, Preschool; Female; Humans; Infections/etiology; Length of Stay; Male; Multiple Trauma/etiology; Postoperative Complications/etiology; Prognosis; Risk Factors; Wounds, Gunshot/classification; Wounds, Gunshot/complications; Wounds, Gunshot/surgery; Wounds, Penetrating/complications; Wounds, Penetrating/surgery; Wounds, Stab/classification; Wounds, Stab/complications; Wounds, Stab/surgery