The purpose of this study is to determine whether drainage after prosthetic repair of incisional abdominal hernias increases or decreases complications such as infection, seromas and hematomas.

Between 3 to 20% of patients who received a midline laparotomy will develop an incisional hernia.

Primary suture of the defect is associated with a recurrence rate between 25 and 50%.Mesh repair is superior with regard to the recurrence (12-20%), but early postoperative complications include infections, hematomas and seromas.

Some advocate the use of drains in order to diminish secretions and complications. Other claim that drains increase the complication's rate.

In the absence of a randomized controlled trial it's not clear whether drainage could influence positively or negatively the occurence of such complications when performing a prosthetic repair of abdominal incisional hernia.

The aim of this study is to answer this question, comparing prospectively two groups of operated patients: the former with drainage and the latter without.

Inclusion Criteria:

• Clinical diagnosis of midline abdominal wall incisional hernia
• Adults of 20 to 80 years old
• ASA I to III
• Inform consent signed by the patient and investigators

Exclusion Criteria:

• Incisional hernia less than 2 cm
• Groin hernia
• Antibiotic treatment before and during hospital admission
• Emergency admission for strangulated incisional hernia
• Immunosuppressing treatment