The notable development and diffusion of prosthetic surgery of the abdominal wall over the last few years has led to the introduction of light weight meshes. The efficacy of inguinal hernia repair with light weight prosthesis, as well as the better or worse biotolerability with respect to those of light weight, remains questionable in literature, where a clear answer still remains to be given. If there exists a connection between the quantity of material implanted, the immunological reaction to the mesh, the induced oxidative stress and the degree of cicatrization, and consequently the long-term result of the efficacy of the operation, remains to be demonstrated. There are few studies on the immunological reaction to polypropylene meshes, and none on the oxidative stress induced by the mesh. Moreover, only one study has been published that clearly correlates the immunological reaction to the amount of prosthetic material, but was carried out on only a few patients.

The aim of this research is to show if there is a relationship between the amount of prosthetic material used and immunological reactions as well as postoperative oxidative stress, and thus to evaluate, if present, the differences in the biological reaction and biotolerability between light-weight and heavy-weight meshes on a statistically significant number of patients.

Double blind randomization. The recruitment of patients will take place in the order that they are referred to the hernia service of the General Surgery and Week Surgery Unit of the University Hospital of Catania. After the examination confirming the diagnosis of inguinal hernia and once surgery has be indicated, informed consent will be obtained from the patient by means of a standardized form. The assignment to group H or group L will be made following a simple criterion of alternation that is completely random: i.e. patient 1 (Group H), patient 2 (Group L).A total of 60 patients will be recruited and divided into the two groups. For group H inguinal hernioplastic surgery will be carried out with the so called "heavy-weight" mesh (about 220 g/m2 of polypropylene), for Group L, on the other hand, the mesh will be of the "light-weight" type (about 40 g/m2).

A preoperative blood test will be carried out to determine the basal levels of IL-6, TNF-alpha, nitrites, GSH and isoprostanes) and 3 postoperative tests (at 6 h, 3 days and 12 days), all samples will be frozen for reference.

All the data from each patient will be collected in a personal file compiled by the surgeon. When all the blood samples are collected a laboratory technician and a biochemist will determine the levels of the above mentioned substances, these data will then undergo statistical evaluation.

Inclusion Criteria:

• All patients affected by primary inguinal hernia

Exclusion Criteria:

• Diabetes
• Corticosteroids treatment
• Immunosuppressive drugs
• Cirrhotic patients
• Chronic inflammatory disease
• Neoplastic patients

All patients affected by primary inguinal hernia