Prophylaxis of Surgical Wound Infection in Incisional Hernia Repair With Topical Antibiotics (PROTOP-PAR)

Prophylaxis of Surgical Wound Infection in Incisional Hernia Repair With Topical Antibiotics (PROTOP-PAR)

Surgical site infection (SSI) is the main complication of surgery. The prevention of superficial SSI by topical prophylaxis is controversial. Human studies on wound lavage with topical solutions (saline, antiseptics or antibiotics) are old and do not yield conclusive results. In experimental conditions there is evidence in favor of the efficiency wound lavage with saline and antibiotic solutions. Clinical studies are needed to demonstrate the safety and efficacy of antibiotic lavage.

Objective. Study of the efficacy of topical antibiotic therapy in the prevention of SSI in patients undergoing incisional hernia repair after abdominal surgery.

Method. Randomized double-blind clinical trial comparing two groups of topical prophylaxis. Follow-up will be 90 days after operation. Data will be collected anonymously and the relationships between the variables will be analyzed using Pearson's chi-square, survival analysis and analysis of risk factors as appropriate. The effect of topical antibiotic on hospital stay, resistance patterns in SSI, and antibiotic serum levels will be analyzed.

Several Surgical site infection (SSI) prevention guidelines have been published over the last 10 years. Topical prophylaxis of the surgical wound with antibiotics or antiseptics is one of the most controversial measures proposed for SSI prevention. Two guidelines (British, Spanish Ministry of Health) explicitly recommend not irrigating surgical wounds with any product. The World Health Organization considers irrigation with antibiotics as an unresolved issue and, together with the Centers for Disease Control, recommends irrigation with a solution of povidone iodine. The other four guides do not mention the measure. In Catalonia, a SSI prevention bundle recommends wound irrigation with saline, with a low level of recommendation.

Therefore, topical prophylaxis with operational wound washings with different solutions has been poorly studied, evokes contradictory recommendations and is not included in the majority of clinical practice guidelines for SSI prevention.

However, a high level of use of wound irrigation at the end of an intervention in actual clinical practice has been observed. In a survey conducted by 2017 and answered by 845 general surgeons of the Spanish Association of Surgeons, before closing the skin, most surgeons (80.6%) irrigate the subcutaneous layer of the wound, either with saline (51.2%), an antiseptic solution (23.8%) or an antibiotic solution (1.5%). Only 19.4% of respondents do not irrigate. In another survey in 2018, focused on colorectal surgeons of two Spanish associations, similar rates of irrigation with saline, antiseptic or antibiotic were used (55%, 28.9% and 2.2%, respectively).

SSI rates after complex incisional hernia repair are higher than previously reported. In a recent paper, this research team observed that patients with SSI after hernia repair showed more prolonged surgical procedures, and a higher one-year recurrence rate. Multivariable analysis revealed the only identified risk factor for SSI to be post-operative sero-hematomas. Patients who developed an SSI required antibiotic agents and daily treatment from one to five months. One of these required the removal of the mesh. SSI rates were high for incisional hernia surgery (16%), and were associated with local complications.

The hypothesis of the study is that topical prophylaxis of the surgical wound with irrigation with an antibiotic solution decreases the rate of postoperative infection in patients undergoing incisional hernia surgery with different levels of contamination.

The study will compare the efficacy of topical prophylaxis with saline with a solution of amoxicillin-clavulanate in the incidence of SSI in incisional hernia repair.

It is a randomized, controlled, multicenter, blind study by observer and patient, with two parallel study groups, phase IV.

Design of study The irrigation of the wound with 0.9% saline will be compared with the irrigation with an active principle solution of a pharmaceutical specialty of proven efficacy (amoxicillin-clavulanate) by parenteral route, administered topically and dissolved in saline.

The two groups of the study will be named: Study Group (irrigation with antibiotic solution) and Control Group (irrigation with saline).

The project has received the Spanish Drug Agency authorization as a low intervention study, a grant from the Spanish Ministry of Health and the Ethics Committee authorization of the Hospital General of Granollers.

Inclusion Criteria:

• Patients who require an elective surgical procedure due to an abdominal wall incisional hernia.

Exclusion Criteria:

• Emergency surgery
• Parastomal hernia
• Patients under treatment with immunosuppressants, corticosteroids and patients on hemodialysis.
• Patients with liver cirrhosis.
• Patients with suspected allergy to bata-lactams antibiotics.
• Patients who have undergone a recent open abdomen surgical technique (up to 30 days pre-intervention), placement of a prosthesis made of synthetic material (mesh) or in which the wound cannot be closed surgery at the discretion of the surgeon.
• Patients defined as grade 5 of the American Association of Anaesthesiologists classification (ASA 5).