the Management of Diverticular Disease

- Glossary

Definition of diverticular disease and classification

We found that there is a great importance to establish clear definitions in the area of diverticular disease. Numerous classifications and modifications describe the various stages of diverticular disease. The first widely used classification by Hinchey was intended as an intra-operative stratification of perforated diverticulitis with abscess or peritonitis enabling surgeons to adjust the surgical approach. It was later modified to preoperative use, incorporating CT findings, ⁽¹⁾.

 Diverticulosis versus diverticular disease

 Diverticulosis of the colon (existence of false diverticula – outpouchings of mucosa and serosa through openings in the muscular layer of the bowel) develops in the majority of individuals in western countries with increasing age and usually remains asymptomatic. Diverticulosis per se should not therefore be considered a disease. The term diverticular disease implies that there are symptoms related to the diverticula, ⁽²⁾.

Symptomatic uncomplicated diverticular disease (SUDD)

The term symptomatic uncomplicated diverticular disease (SUDD) is used in some countries for patients with diverticula who experience abdominal symptoms (e.g. abdominal pain and bloating) and changes in bowel habit (e.g. diarrhea, constipation or alternating bowel habit) in the absence of inflammation. However, the term has not found general acceptance and a uniform definition does not exist. Currently, there is little evidence on how to manage SUDD, ⁽¹⁾.

Diverticulitis

The term diverticulitis describes a peri-diverticular inflammation of the bowel wall and usually the surrounding tissue. Diverticulitis can be acute or chronic and complicated or uncomplicated with possible complications including abscess, perforation, fistulas, obstruction and bleeding. The severity of acute diverticulitis, mainly determined by cross-sectional imaging (CT scan, ultrasound) and laboratory tests (C-reactive protein), is decisive and guides management and treatment. In general, uncomplicated acute diverticulitis is differentiated from complicated acute diverticulitis. The cut-off is poorly defined but depends on the degree of inflammation, ⁽³⁾.

Acute uncomplicated diverticulitis is inflammation in a diverticula-bearing bowel segment and the surrounding tissue without signs of perforation (extraluminal air) or abscess formation, ⁽⁴⁾.

Acute complicated diverticulitis: Typical complications of acute diverticulitis occur if the inflammatory process extends beyond the colonic wall. However, peridiverticulitis alone is not considered complicated disease. A covered perforation with air bubbles in proximity to the bowel, intra-abdominal abscess adjacent to the inflamed segment (Hinchey Ib, according to Wasvary) or distant (Hinchey II) and free perforations with purulent or faecal peritonitis (Hinchey III and IV) represent the major manifestations of acute complicated diverticulitis, ⁽⁴⁾, (tables 1 & 2).

Acute complicated diverticulitis comes with considerable mortality. Mortality risk increases even more in the case of free perforations with peritonitis. Both the risk of a subsequent free perforation and the risk of death decrease with the number of previous episodes. The first episode of complicated diverticulitis is by far the most dangerous, ⁽⁴⁾.

Chronic diverticulitis: If an acute diverticulitis does not resolve completely, chronic diverticulitis can develop. Wall thickening or chronic mucosal inflammation in the absence of stenosis is called chronic uncomplicated diverticulitis. Complicated chronic diverticulitis may progress to include either stenotic disease, which may lead to acute bowel obstruction, or fistulation most commonly to the urinary tract, or both, ⁽⁴⁾.

Diverticular bleeding: According to ESCP statement, diverticular bleeding is reported to account for about 35% of painless lower gastrointestinal bleeding and occurs in up to 50% of elderly patients with diverticulosis. Frequently, the bleeding site cannot be identified, and coexisting diverticula may then falsely be reported as the bleeding cause. Diverticular bleeding is arterial and occurs from rupture of the intramural branches of the marginal artery at the dome or neck of the diverticulum. Trauma from mechanical or chemical causes within the lumen of the diverticulum leads to injury to the penetrating vessels and bleeding. Histopathological examination of diverticular bleeding sites has shown absence of diverticulitis, but bleeding may occur during inflammation as well. If surgery is required, precise localization of the bleeding site is crucial for any surgical procedure. Colonic resections in patients with diverticular bleeding and an unclear localization have shown a postoperative mortality of 43% in comparison to 7% in patients with defined bleeding localization. There are separate guidelines for the management of lower gastrointestinal bleeding which is therefore not part of this guideline, ⁽⁵⁾.