Pictorial review of normal postoperative cross-sectional imaging findings and infectious complications following laparoscopic appendectomy.

Laparoscopic appendectomy is increasingly accepted as the preferred surgical treatment for acute appendicitis and represents one of the most common emergency operations performed in both adult and paediatric populations. However, in patients with perforated appendicitis laparoscopy is associated with an increased incidence of postoperative intraabdominal infections compared to open appendectomy. Nowadays urgent imaging is commonly requested by surgeons when postoperative complications are suspected. Due to the widespread use of laparoscopy, in hospitals with active surgical practices clinicians and radiologists are increasingly faced with suspected postappendectomy complications. This pictorial essay illustrates the normal cross-sectional imaging findings observed shortly after laparoscopic appendectomy and the spectrum of appearances of iatrogenic intraabdominal infections observed in adults and adolescents, aiming to provide radiologists with an increased familiarity with early postoperative imaging. Emphasis is placed on the role of multidetector CT, which according to the most recent World Society of Emergency Surgery (WSES) guidelines is the preferred and most accurate modality to promptly investigate suspected intraabdominal infections and highly helpful for correct therapeutic choice, particularly to identify those occurrences that require in-hospital treatment, drainage or surgical reintervention. In teenagers and young adults MRI represents an attractive alternative modality to detect or exclude iatrogenic abscesses without ionising radiation. Teaching points • Laparoscopic appendectomy is the preferred surgical treatment for uncomplicated acute appendicitis • In perforated appendicitis laparoscopy results in increased incidence of intraabdominal infections • Multidetector CT promptly assesses suspected iatrogenic intraabdominal infections • Interpretation of early postoperative CT requires knowledge of normal postsurgical imaging findings • Postsurgical infections include right-sided peritonitis, intraabdominal, pelvic or liver abscesses.