Chapter 69

Diverticular Disease

Lauren A. Kosinski, Kirk Ludwig, and Mary F. Otterson

Key Points

1 Diverticulosis and its complications are common in Western societies.

2 Sigmoid and left colon involvement predominate in non-Asian industrialized nations; the rectum is

spared.

3 Lack of dietary fiber, colonic anatomy, and disordered colonic motility are likely contributors to the

development of diverticulosis.

4 New data suggest that uncomplicated diverticulitis may be an inflammatory rather than an infectious

process.

5 Computed tomography (CT) imaging markedly improves diagnostic accuracy and treatment

planning.

6 Early, judicious use of contrast enema studies or colonoscopy can safely help distinguish diverticular

stricture from cancer.

7 Antibiotic therapy, bowel rest, and percutaneous drainage of diverticular abscesses can often convert

surgical emergencies into elective operations.

8 Bowel resection with primary anastomosis and temporary, diverting loop stoma is favored in acute

cases when possible; single-stage operations are preferred for elective cases.

9 Early enthusiasm for emergency laparoscopic washout and repair of diverticular perforations has not

been supported by prospective, randomized trials.

10 Criteria for elective colon resection for diverticulitis are evolving and trending toward more

restrictive indications.

Diverticular disease (DD) is one of the most common problems treated by surgeons, and management

strategies have evolved significantly in the last 15 years. A short time ago, virtually all cases of acute

diverticulitis were treated as surgical emergencies. Patients routinely underwent staged procedures and

were taken to the operating room for sigmoid colectomy and temporary end-colostomy within hours of

admission. Surgical and radiologic innovations have introduced less invasive options for managing even

complex disease. Surgery, when necessary, is often performed electively or semi-electively.

Key among recent major shifts in the diagnosis and management of DD are (a) strategies for

converting diverticular surgical emergencies into single-stage, elective operations with avoidance of a

colostomy; (b) utilization of computed tomography (CT) imaging for diagnosis and CT-guided

percutaneous drainage of diverticular abscesses; (c) reconsideration of indications for elective surgery;

and (d) emergence of laparoscopic surgical techniques as state-of-the-art approaches for DD. Fear that

younger patients with diverticulitis or older patients with a single episode of diverticulitis were at

increased risk of perforated diverticulitis and colostomy construction has been allayed by data that show

no increased risk. These data and recognition that even elective resection for DD may have higher

complication and colostomy rates than elective colon cancer resections

1 have fueled concern that the

cure might be worse than the disease and are shaping more stringent guidelines for elective resection.

CLASSIFICATION

1 Diverticulosis refers to the presence, whether symptomatic or asymptomatic, of colonic diverticula. In

common medical usage, this refers to the presence of pseudodiverticula in which mucosa and submucosa

have herniated through the circular layer of the muscularis propria, a very common acquired condition

in Western societies. True diverticula are rare. DD refers to the broad range of symptoms and findings

associated with diverticulosis and includes diverticulitis, an inflammatory and often infectious process.

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Inflammation can be acute or chronic. Acute inflammation can present with a pericolonic phlegmon,

colon perforation leading to focal abscess formation, or generalized purulent or fecal peritonitis. Acute

and chronic inflammation can result in fistula formation between the involved bowel segment and the

bladder, vagina, or skin. With chronic or recurrent inflammation, scarring of the involved segment can

cause bowel wall thickening, dysmotility, and stricture, which may present as altered bowel habit or

even frank obstruction.

ANATOMY

2 Colonic diverticula are pulsion diverticula that occur in predictable sites on the bowel wall. Likewise,

the pattern of segmental involvement of the colon and its progression are predictable. The sigmoid

colon is at highest risk and is affected in 95% of patients. Involvement is isolated to the sigmoid colon

in 30% to 60% of cases. Total colonic involvement occurs in 7% to 10% of cases.2 The rectum is almost

always spared. This segmental pattern of involvement is not observed in Asia, where 70% of

pseudodiverticula are isolated to the right colon and cecum. The reason for this discrepancy is not

known. Right colon pseudodiverticula are more likely to be solitary and tend to originate near the

ileocecal valve.3,4 When true colonic diverticula develop, they are also more likely to be right sided;

however, they are still much less common than pseudodiverticula of the right colon.

INCIDENCE

Diverticulosis is rare in nonindustrialized, less affluent societies. The French surgeon Alexis Littre is

credited with first describing diverticulosis in 1700, but it was not until the mid-1800s that there were

reports in the medical literature about the disease process and its treatment.5 The prevalence of

diverticulosis increased after the industrial revolution and through this century. Even before 1940, it

was recognized infrequently; retrospective reviews of colon radiographs and pathologic specimens

record an incidence of 5% to 10%.6 An incidence of 46% in people 51 years of age and older was

reported by Hughes from postmortem studies in 200 cadavers (Table 69-1).7 Incidence as a function of

gender varies by study, some studies citing an increased incidence among men and others finding a

higher incidence among women. It may be that the spectrum of complications and the age at which they

develop are gender specific. The majority of people with diverticulosis remain asymptomatic; only 15%

to 30% will go on to develop symptomatic disease.8 Of these, only 30% will require operative

treatment.9 In the United States in 1998, 2.2 million cases of DD were treated at an estimated cost of $2

billion.10 In 2005, DD was the primary diagnosis in 307,000 hospital discharges and accounted for 1.6

million inpatient days of care.11

Table 69-1 Incidence of Diverticulosis in Western Society

ETIOLOGY

3 Neither the etiology of diverticulosis nor factors causing progression to symptomatic disease have

been rigorously defined, but lack of dietary fiber, colonic dysmotility, and colonic structural

abnormalities and age-related changes have all been implicated. There may be an association between

irritable bowel syndrome (IBS) and diverticulitis, the microbiome may be a mediator in diverticular

inflammation, and idiopathic inflammation may also contribute to the DD spectrum.

Structural/Anatomic Factors

In the colon, the outer, longitudinal layer of the muscularis propria is condensed in three longitudinal

bands called the taeniae coli. One of these runs along the mesenteric aspect of the colon; the other two

are antimesenteric in location (Fig. 69-1). Mesenteric blood vessels encircle the colon and penetrate the

circular muscle in the intertaenial areas between the mesenteric taenia and the two antimesenteric

taeniae. Pseudodiverticula develop at areas where these vessels pass through muscle.12 Postmortem

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