Currently, this classification has been condensed into four groups for general use, without a subdivision of the clean category and in the modified form it is categorized into four categories [10] 1. Clean sites (wounds):  • Elective (not urgent or emergency).  • Primary closed.  • No acute inflammation or transection of tracheobronchial, biliary, gastrointestinal, oropharyngeal tracts.  • No technique breaks. 2. Clean-contaminated sites (wounds):  • Emergency or urgent cases that are otherwise “clean.”  • Elective procedures.  • Reoperation via “clean incision” within 7 days.  • Blunt trauma, intact skin, and negative exploration. 3. Contaminated sites (wounds):  • Acute nonpurulent inflammation.  • Major technique break or major spill from hollow organs.  • Entrance of genitourinary or biliary tracts in presence of infected urine or bile, respectively.  • Penetrating trauma less than 4 h old.  • Chronic open wounds to be grafted or covered. 4. Dirty sites (wounds):  • Purulence or abscess.  • Preoperative perforation of tracheobronchial, biliary, gastrointestinal, oropharyngeal tracts.  • Penetrating trauma more than 4 h old.