REsiDENT 1 (Re-assessment of Appendicitis Evaluation during laparoscopic appendectomy: Do we End a Non-standardized Treatment approach and habit?): Peritoneal irrigation during laparoscopic appendectomy - Does the grade of contamination matter? A prospective multicenter resident-based evaluation of a new classification system

Background: Laparoscopic appendectomy has progressively gained acceptance as the standard of care for acute appendicitis. Focusing on the incidence of postoperative intra-abdominal abscess after a laparoscopic appendectomy, discordant data have been reported ranging from 1.5 to 20%. Besides, evidence advocating advantages from peritoneal irrigation over suction only are lacking. Most studies are burdened by a high level of heterogeneity regarding the severity of the appendicitis and modalities of peritoneal irrigation. One of the main drawbacks is the lack of an accepted classification for different degrees of appendicitis and peritoneal contamination. The aim of the study is to introduce a classification to clarify the relationship between grade of appendicitis, contamination, and postoperative incidence of IAA considering the surgeon's attitude toward irrigation or suction alone. Preoperative, intra-operative, and postoperative predictive factors for infectious complication will also be assessed. This study is meant to be the first Italian multicenter resident-based observational study. Methods: Patients suffering from acute appendicitis will be enrolled during a 1-year period, according to inclusion and exclusion criteria. Participants will fill an online form reporting all clinical and intra-operative data of each patient undergoing a laparoscopic appendectomy. General surgery residents will be responsible for data collection. Our proposal of classification is based on the histological grade of appendicitis and intra-operative degree of peritoneal contamination. For each grade, a progressively increasing score is assigned. Discussion: The observational nature of this study is mandatory to examine surgeons' attitude toward peritoneal contamination during laparoscopic appendectomy for appendicitis. Identification of different severity grades of acute appendicitis and their relationship with the development of postoperative abscesses is necessary. The resulting classification and score, even considering peritoneal lavage or suction alone, will define risk classes of peri-appendiceal contamination each one related to a specific incidence rate of postoperative IAA. Nowadays, maximum effort should be made to reach the best procedural standardization and surgical decision-making should be supported by solid evidence, especially in an emergency surgery setting.