This study evaluates the intraabdominal abscess rate after laparoscopic appendectomy in complicated acute appendicitis performing irrigation of the abdominal cavity or only suction without lavage.

Despite the available literature for and against the irrigation of the abdominal cavity in complicated acute appendicitis, in the current practice of this and other centres, the irrigation and no irrigation is made equally depending on the surgeon who performs the intervention.

Those who systematically irrigate the abdominal cavity in laparoscopic appendectomies do it as an inherited act from open surgery and those who systematically do not irrigate the abdominal cavity base their choice in theories such as abscess migration due to the irrigation and difficulty of the suction of all the irrigated fluid, spreading, therefore, the infection.

The intention of the investigators is to provide evidence about this technique in order to either systematize peritoneal irrigation in laparoscopic appendectomy for complicated appendicitis or avoid an unnecessary gesture, if it were established so.

This will be a prospective, randomized clinical trial involving patients who present to the hospital with complicated acute appendicitis. Power calculation was based on abscess rate in the investigators' hospital calculated retrospectively (15%) Subjects will be those patients above 18 y.o. who are found to have complicated acute appendicitis (defined as perforated appendicitis before or during surgery, gangrenous appendicitis and/or purulent peritonitis).

The final decision to include a patient in the study will made after complication has been visually confirmed during surgery. The randomization assignment will be made known at the initiation of the operation, and confirmation of complication will confirm the patient will utilize the next randomization slot.

The irrigation group will have suction irrigator set up with a 1 liter bag of normal saline. The surgeon must use at least 300 ml of this bag but may use as much as they choose.

The no irrigation group will have the suction irrigator set up without the saline attachment. This will leave them with the capacity for suction only. Since several suction devices exist, this will assure the same type of suction for both groups.

After the operation, both groups will be managed in the same manner. When the patient is tolerating a regular diet, on oral pain medication and has been afebrile for over 12 hours, they will be discharged on oral antibiotics to complete a course of 7 days. If the participants stay until the 5th post-operative day, a white blood cell count will be checked, which if it is normal, they will be discharged to home without antibiotics.

Inclusion Criteria:

• Patients with complicated acute appendiccitis
• Laparoscopic approach

Exclusion Criteria:

• Open approach
• Medical or psychiatric condition of the patient that compromises the informed consent authorisation
• Non complicated acute appendicitis
• Underage patients (<18)
• Refusal to participate in the study.