Identification of the Optimal Treatment Strategy for Complex Appendicitis in the Pediatric Population
Identification of the Optimal Treatment Strategy for Complex Appendicitis in the Pediatric Population
Aim of this study is to evaluate the effect of different treatment strategies on overall
 complications, health related-Quality of Life (hr-QOL) and costs among two subtypes of
 complex appendicitis in children (<18 years old).

 Main research questions: What is the difference in overall complications at three months
 between:

 Subgroup 1 (complex appendicitis without abscess/mass formation): Laparoscopic (LA) and open
 appendectomy (OA) Subgroup 2: (complex appendicitis with abscess/mass formation):
 Non-operative treatment (NOT) and direct appendectomy
Up till now initiated research projects worldwide mainly focus on simple appendicitis
 (questioning the necessity of an appendectomy). However, complex appendicitis is associated
 with significant morbidity (up to 30%), prolonged hospital stay and high costs.
 Identification of the optimal treatment strategy for children with complex appendicitis is
 therefore essential. Heterogeneity in the treatment of complex appendicitis still exists in
 daily practice and reflects the lack of high-quality data and emphasizes the need for
 well-designed studies. Complex appendicitis can be divided into two subtypes:

 1. Complex appendicitis without mass/abscess. (subgroup 1) Although (inter)national
 guidelines agree that appendectomy should be usual care, the optimal approach (open or
 laparoscopy) is unclear. Laparoscopic appendectomy (LA) is increasingly applied both in
 adults (80%) and children (60%). Benefits reported for LA in children are, but not
 limited to, less superficial site infection (SSI), reduced length of hospital stay and
 significant less postoperative bowel obstruction compared with open appendectomy (OA).
 Reluctance for usage of LA in this specific subgroup, however, remains due to the
 potential higher incidence of post-appendectomy abscess formation (PAA) reported.
 However, the quality of studies on this topic is low and there is considerable
 inconsistency in results.

 2. Complex appendicitis with mass/abscess. (subgroup 2) The recommendation made in our
 national guideline (to perform direct appendectomy in this subgroup) is not in line with
 the available literature. A recent Cochrane review on this topic could only include two
 trials and stated that no firm conclusions could be drawn. An older systematic review,
 including 7 studies in children, concluded that non-operative treatment (NOT) led to
 fewer complications, specifically SSI and PAA, when compared to direct appendectomy.
 Still the recommendation from our national guideline is to perform a direct appendectomy
 based upon good experiences in the pediatric academic centers.

 In order to investigate the optimal treatment for children with complex appendicitis we will
 perform a nationwide, multi-center, comparative, prospective cohort study. For the purpose of
 this study, treatment strategies will be standardized among the participating hospitals in
 order to reduce heterogeneity. Prospectively derived, high quality data will be sufficient to
 answer the research questions regarding the optimal treatment strategy for each subtype of
 complex appendicitis in the pediatric population. As it is a non-randomized prospective
 cohort study, propensity score matching technique will be performed in order to estimate the
 effect of the treatments adjusted for potential confounders.
Inclusion Criteria:

 Eligible for inclusion are all children <18 years old that need to undergo treatment for
 the suspicion of complex appendicitis. Suspicion of complex appendicitis is based upon the
 following predefined criteria:

 4 or more points on our scoring system developed to predict complex appendicitis. The
 diagnostic accuracy of this scoring system is 91% (Range: 84-98%). This scoring system
 consists of five variables (clinical, biochemical and radiological,each awarded points). In
 case the total score is 4 or more points, the patient is likely to have complex
 appendicitis. Variables included in the scoring system are:

 -  Diffuse abdominal guarding (3 points)

 -  CRP level more than 38 mg/L (2 points)

 -  Signs on ultrasound / imaging indicative for complex appendicitis (2 points)

 -  More than one day abdominal pain (2 points)

 -  Temperature more than 37.5 degrees Celsius (1 point)

 Or

 High index of suspicion of complex appendicitis by the treating physician. If this is the
 case, the treating physician will make pre-treatment note upon what clinical, biochemical
 or radiological variable the high index of suspicion is based.

 Exclusion Criteria:

 -  Adult patients (=18 years old)

 -  Children with a suspicion of simple appendicitis (based upon the previous mentioned
 scoring system and radiological features)