title: Treatment of patients with acute colonic diverticulitis complicated by abscess formation: A systematic review.
abstract: OBJECTIVE
  This study aimed to systematically review the literature and present the evidence on outcomes after treatment for acute diverticulitis with abscess formation. Secondly, the paper aimed to compare different treatment options.
  
  
  METHODS
  PubMed, EMBASE and the Cochrane Library were searched. Two authors screened the records independently, initially on title and abstract and subsequently on full-text basis. Articles describing patients treated acutely for Hinchey Ib and II were included. Results were presented by treatment, classified as non-operative (percutaneous abscess drainage (PAD), antibiotics, or unspecified non-operative strategy), PAD, antibiotics, or acute surgery. The outcomes of interest were treatment failure, short-term mortality, and recurrence.
  
  
  RESULTS
  Of 1723 articles, 42 studies were included, describing 8766 patients with Hinchey Ib-II diverticulitis. Observational studies were the only available evidence. Treatment generally failed for 20% of patients, regardless of non-operative treatment choice. Abscesses with diameters less than 3 cm were sufficiently treated with antibiotics alone, possibly as outpatient treatment. Of patients treated non-operatively, 25% experienced a recurrent episode during long-term follow-up. When comparing PAD to antibiotic treatment, it appeared that PAD lead to recurrence less often (15.9% vs. 22.2%). Patients undergoing acute surgery had increased risk of death (12.1% vs. 1.1%) compared to patients treated non-operatively. Of patients undergoing PAD, 2.5% experienced procedure-related complications and 15.5% needed adjustment or replacement of the drain.
  
  
  CONCLUSIONS
  Observational studies with unmatched patients were the best available evidence which limited comparability and resulted in risk of selection bias and confounding by indication. Diverticular abscesses with diameters less than 3 cm might be sufficiently treated with antibiotics, while the best treatment for larger abscesses remains uncertain. Acute surgery should be reserved for critically ill patients failing non-operative treatment. Further research is needed to determine the best treatment for different sizes and types of diverticular abscesses, preferably randomized controlled trials.
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, Herlev Ringvej 75, 2730 Herlev, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: rasmusg90@gmail.com.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Gregersen
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, Herlev Ringvej 75, 2730 Herlev, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Laura Quitzau
authors.initials: LQ
authors.lastname: Mortensen
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, Herlev Ringvej 75, 2730 Herlev, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Burcharth
authors.affiliation: Department of Surgery, Hvidovre Hospital, Kettegård Alle 30, 2650 Hvidovre, Denmark.
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Pommergaard
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, Herlev Ringvej 75, 2730 Herlev, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Rosenberg
mesh_terms: D018784:Abdominal Abscess / Q000209:etiology / Q000628:therapy*; D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003082:Colectomy; D004239:Diverticulitis, Colonic / Q000150:complications / Q000628:therapy*; D004322:Drainage; D006801:Humans; D064887:Observational Studies as Topic; D012008:Recurrence; D017211:Treatment Failure
chemical_list: D000900:Anti-Bacterial Agents
keywords: Abscess; Diverticulitis; Systematic review; Treatment