| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Original Research |
1 Both authors: Department of Radiology, University of Maryland Medical Center, 22 S Greene St., Baltimore, MD 21201-1595.
Received January 7, 2005;
accepted after revision July 16, 2005.
Address correspondence to B. Daly
(bdaly{at}umm.edu).
Abstract
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
50 years) now than previously recognized. We reviewed the
CT findings, clinical features, and demographic data of a cohort of patients
who presented with acute diverticulitis at an urban U.S. academic medical
center. MATERIALS AND METHODS. We used our hospital and radiology databases to identify 104 adult patients with both CT and clinical diagnoses of acute diverticulitis. Clinical parameters recorded included age, sex, ethnicity, in- or outpatient management, and therapy (medical treatment, percutaneous drainage, or surgery). CT studies were evaluated for the site of diverticulitis; associated complications; and the presence of abdominal obesity, as determined by measurement of sagittal abdominal diameter.
RESULTS. The study group was composed of 55 men and 49 women (age
range, 22-88 years; mean age, 52.2 years; median age, 49.0 years). Fifty-six
(53.8%) were 50 years old or younger, and 22 were 40 years old or younger.
Forty-one complications were noted in 38 patients (36%). There was no
significant age difference between the 50 and > 50 years old age
groups for hospital admission (90 patients, 86.5%), medical therapy (76,
73.1%), or surgery or percutaneous abscess drainage (28, 26.9%). Abdominal
obesity measured by sagittal abdominal diameter was present in 48 (85.7%) and
37 (77%) of the 50 and > 50 years old age groups, respectively. The
mean sagittal abdominal diameter for patients 50 years old (27.0 cm) was
greater than that for patients > 50 years old (25.6 cm) (p =
0.05).
CONCLUSION. In this urban population, acute diverticulitis occurred more frequently in patients 20-50 years old than previously recognized. This group had significantly greater abdominal obesity than the older group. Severe disease requiring hospital admission, surgery, or percutaneous drainage (or both surgery and percutaneous drainage) was common in all age groups.
Keywords: colon • CT • diverticulitis • obesity
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Acute diverticulitis is the most common complication of colonic diverticulosis and is one of the most frequently encountered acute diseases of the colon. It begins as a localized intramural infection in a segment affected by diverticulosis, with subsequent development of localized pericolic inflammation. Colonic perforation, abscess formation, or generalized peritonitis may occur [5, 10]. Colonic strictures and fistulas to other organs are other important complications [5, 10, 11]. Serious complications are more likely if acute diverticulitis is initially unrecognized or misdiagnosed [10, 12].
Acute diverticulitis traditionally has been considered a disease of patients more than 50 years old by many authorities [1-3, 6]. It has been considered a rare diagnosis in a young adult presenting with abdominal pain, with few reports in the published literature. In one report, acute diverticulitis was considered more aggressive in younger patients than in older adults [12].
|
|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The findings of all CT studies were based on the initial interpretation of the attending radiologist, each of which was confirmed on review by a single experienced abdominal radiologist. The presence, location, and extent of findings of acute diverticulitis were noted, as were any related complications. Data about patient height and weight were incomplete for many patients as is typical in the setting of acute illness, so body mass index (BMI) could not be calculated as a measurement of obesity. Instead, the presence of abdominal obesity was determined on each CT study by measurement of the sagittal abdominal diameter. This distance was measured in centimeters between the anterior and posterior skin at the level of the fourth lumbar vertebra (Fig. 1). This measurement has been used as an index of abdominal obesity in prior studies [14-16]. Normally, these measurements are determined in clinical practice by the use of dedicated large calipers applied to the skin of the patient, but CT measurements of sagittal abdominal diameter have been shown to correlate closely with skin measurements [14].
Sagittal abdominal diameter values of greater than 25 cm have been determined to be indicative of obesity and predictive for an increased risk of obesity-associated morbidity [15]. In another study, the mean sagittal abdominal diameter values of 24.5 cm in women and 23.7 cm in men have been shown to correspond to BMI values of 31.4 and 29.0 kg/m2, respectively [14]. BMI values of 25 and 30 kg/m2 are widely recognized as indicative of overweight status and obese status, respectively.
Patients were stratified into seven groups according to age: 21-30, 31-40, 41-50, 51-60, 61-70, 71-80, and more than 80 years. This retrospective study was approved by the institutional review board at our medical center.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The sites of disease included the sigmoid colon (n = 71 [68.3%]),
descending colon (n = 15 [14.4%]), ascending colon (n =6
[5.7%]), cecum (n = 6 [5.7%]), and transverse colon (n = 3
[2.8%]). Five patients had disease involving two adjacent segments. The most
common presentation was abdominal pain, noted in 93 patients (89%). Only 36
(51%) of 71 patients with sigmoid involvement had pain localized to the left
lower quadrant. Nine (75%) of 12 patients with right colonic diverticulitis
had pain localized to the same side, and this finding was noted more often in
patients 50 years old (9 of 12). Thirty-four patients (33%) presented
with fever, and 39 (37%) presented with leukocytosis.
Forty-one complications were noted on CT in 38 patients (36%): 19 were
50 years old and 22 were > 50 years old. The complications were as follows
(Table 1): colon perforation,
n = 22; abscess, n = 13; fistula formation, n = 4
(3 colovesical, 1 colovaginal) (Fig.
3); and stricture formation or bowel obstruction, n = 3.
Seventy-six patients (73.1%) ( 50 years old, n = 42; > 50
years old, n = 34) had conservative medical therapy, and 28 (26.9%)
( 50 years old, n = 14; > 50 years old, n = 14) had
surgery or percutaneous abscess drainage. Ninety patients (86.5%) required
hospital admission. Twenty-two patients had a history of multiple attacks
( 50 years old, n = 13;> 50 years old, n = 9).
Thirteen patients (12%) were immunosuppressed: nine were on antirejection
therapy after having undergone solid organ transplantation and four patients
were on chemotherapy for treatment of lymphoma or leukemia. The CT findings
were not more severe in the immunosuppressed group than in the overall group.
Complications were seen in four (31%) of the 13 immunosuppressed patients
compared with 36% of the overall group.
|
|
|
50 years old, 27.0 cm) was
greater than that for older patients (> 50 years old, 25.6 cm), and this
difference was statistically significant (p = 0.05, Student's
t test) (Fig. 4). An
even greater difference in the mean sagittal abdominal diameter values was
noted between younger patients ( 40 years old, 27.7 cm) and older patients
(> 70 years old, 24.9 cm) (p =0.02, Student's t test).
Using sagittal abdominal diameter measurements on each CT study, we determined
that abdominal obesity was present in 85 (82%) of all 104 patients and in 48
(85.7%) and 37 (77%) of the 50 and > 50 years old age groups,
respectively. Seven patients (7%) were overweight (BMI, 25-30
kg/m2), and 12 (11%) had a normal weight (BMI, < 25
kg/m2). |
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Men comprised 63.6% of the patients 50 years old. This predilection of
diverticular disease in younger men is consistent with the findings of other
studies [4,
9,
20-23].
A slightly higher percentage of patients (29.2%) > 50 years old were
managed surgically compared with 26.8% 50 years old. Some authors have
characterized acute diverticulitis in younger patients as being a more
aggressive disease than in older patients
[8,
12,
20,
23] and advocate early surgery
for all patients < 40 years old, even for a first attack
[8,
12,
23]. In our study the
complication rate was slightly lower in the group of patients 50 years
old (58%) compared with the group > 50 years old (69%); we did not find
evidence for more virulent disease behavior in younger patients
(Table 1). Another study
[21] also has refuted an
increased incidence of more severe disease in younger patients.
Our experience suggests that although acute diverticulitis in younger patients appears to be increasing in frequency, most cases initially can be treated successfully without surgery. Other reports agree with our findings and have not noted a greater need for surgery as the initial treatment in young patients, especially if the disease is in the left colon [21, 24]. However, our study group included no Hispanic patients, an ethnic group in whom virulent acute diverticulitis has been described at an early age [20], and the clinical course of our patients may not be representative of all young adults with this disease. Overall, the findings that 86.5% of patients in our study group required hospitalization, 36% had complications, and 27% needed surgery or percutaneous drainage should underline the fact that in most patients acute diverticulitis is a severe illness.
One factor that may contribute to more severe disease in younger patients
noted in some prior reports is the potential for a delay in the diagnosis of
acute diverticulitis due to a low index of suspicion for this disease in young
adults. Because it has been widely considered as rare in patients younger than
40 years old, acute diverticulitis may not be considered in the differential
diagnosis of abdominal pain in young patients. The most common presentation in
our group was abdominal pain, noted in 93 patients (89%). Of note is the fact
that although 71 patients (68.3%) had sigmoid disease, only 36 (51% of this
subgroup) had pain localized to the left lower quadrant, possibly due to the
variable location of the sigmoid colon. In one study, Schweitzer et al.
[21] noted that only three of
16 young patients ( 40 years) had a correct preoperative diagnosis of
acute diverticulitis. Serious complications have been noted to be more likely
if acute diverticulitis is unrecognized
[10,
12]. Poor localization of
clinical symptoms underscores the value of CT for use in making the diagnosis
of acute diverticulitis.
Right-sided diverticulitis has been associated with younger age at
presentation in other reports
[11] and was present more
often in younger patients in our study also (9 of 12 patients 50 years
old). Nine of these 12 patients with right-sided involvement (cecum,
n = 6; ascending colon, n = 6) had pain localized to the
right side. Cecal diverticulitis has been considered to be a diagnosis rarely
made preoperatively [11,
25] but should be identifiable
on CT provided that it is considered in the differential diagnosis
[25]. In our patient cohort,
only one of 12 patients with rightsided diverticulitis required surgical
therapy, suggesting that CT diagnosis contributed to appropriate conservative
management.
Leukocytosis and fever were inconsistent signs associated with diverticulitis in our study, being present in 37% and 33% of patients, respectively, again emphasizing the value of CT for diagnosis. CT allows accurate staging of the inflammatory process, reaching a sensitivity and specificity of up to 100% [13]. CT can be used to identify the important complications of intestinal perforation, abscess, and fistula formation and therefore can have a direct impact on the treatment of the patient. Contrast enema studies have been advocated in the past and are requested by surgeons still, but these studies are of limited value and are less well tolerated by acutely ill patients. Contrast enemas were performed in only two patients in our study group.
A history of recurrent episodes of acute diverticulitis (as many as five
attacks) was noted in 22 patients (21.2%), with this complication being
slightly more common in patients 50 years old (n = 13) than in
patients > 50 years old (n = 9) and no difference in sex
distribution. Clearly, the risk of recurrent disease is of importance in young
patients with a potentially longer lifespan, and this is one of the reasons
that has influenced some authors to recommend surgery more frequently in
younger patients with acute diverticulitis than in older patients
[8,
12,
23].
There were 52 white, 50 African American, and two Asian patients in our study group. The mean ethnic distribution for patients visiting our emergency department during the study interval was 79% African American, 19% white, and 2% other races, suggesting that acute diverticulitis may be more common in white patients, given that 50% of our patients came from an ethnic group comprising only 19% of our emergency department population. No Hispanic patients were included in our group, although young male patients of this ethnicity have been described previously as a group at increased risk for acute diverticulitis [20-23]. The lack of Hispanic patients in our cohort is likely due to the small percentage of this ethnic group in our local population.
Our medical center has large transplantation and cancer programs, which may explain the presence of 13 immunosuppressed patients in our study group. Patients on antirejection therapy for transplantation or on chemotherapy for cancer are predisposed to infection from all sources, although these patients did not experience more complications of diverticulitis than the overall group. Immunosuppressed patients with abdominal pain or fever are more likely to be examined early with CT and treated with broad-spectrum antibiotics; these factors may account for the absence of more severe disease in this group.
Authors of nonradiologic studies have noted a strong association between
acute diverticulitis and obesity
[19-21,
23], which is in agreement
with our findings. As with the decreasing average age of patients with acute
diverticulitis, the increasing frequency of this disease in obese patients has
received little attention in the radiology literature. Using sagittal
abdominal diameter measurements on CT studies, we noted that abdominal obesity
was present in 85 (82%) of 104 patients in our study group. Obesity was more
marked in younger patients (85.7% 50 years old vs 77% > 50 years old).
Sagittal abdominal diameter values were largest in the youngest patients (
40 years) compared with the oldest ones (> 70 years) (p = 0.02),
indicating that obesity and acute diverticulitis were most closely associated
in the youngest adults (Fig.
4).
High-fat, low-residue, fiber-deficient diets can be postulated as possible causes of the rising frequency of acute diverticulitis in younger members of our urban population study group. Statistics for obesity levels in the United States show an overall increase in the prevalence of obesity from 14% to 30% in the decades between 1980 and 2000. The percentage of the U.S. population that is overweight has at the same time increased from 46% to 64% [26].
Limitations
Some limitations were present in our study. Adenocarcinoma may coexist
within colon affected by diverticulosis and on occasion may simulate acute
diverticulitis if the tumor perforates. We do not have comprehensive follow-up
data on all 104 patients, but most were offered and underwent endoscopic colon
evaluation after the acute phase of their illness to exclude this possibility,
in accordance with the policy of our gastroenterology service. As noted
earlier, the mean follow-up period after presentation for our patients was
16.7 months (range, 3-48 months). On review of the medical records, we did not
detect any missed perforated colon cancers that we believe would have likely
come to medical attention during this time.
Our study is based on experience in a single urban U.S. academic medical
center, and the patient population at suburban or rural medical centers may
have different characteristics related to less obesity and greater use of
high-fiber diets. However, a single study of 248 cases in a rural population
noted acute diverticulitis in 29 (12%) of young patients ( 40 years) and
an association with obesity
[20]. Although this evidence
is limited, it suggests that our results may be reproducible elsewhere given
the ubiquitous dietary patterns throughout the United States.
Our study did not include patients at our medical center who were diagnosed with acute diverticulitis but did not undergo abdominopelvic CT. Those patients may have had other studies such as water-soluble contrast enema or no imaging studies. However, because CT has been the imaging study of choice for acute diverticulitis at our medical center for many years, the number of patients not included is thought to be small.
As noted earlier, standard BMI data were not available to diagnose obesity, but we believe an adequate substitute indicator—sagittal abdominal diameter—was used. It is important to note that abdominal obesity, as opposed to total or peripheral obesity, has become an important predictor of obesity-associated diseases such as atherosclerotic heart disease, hypertension, and diabetes mellitus [15]. We suggest that acute diverticulitis may be added to that list.
The age distribution of our study cohort clearly suggests a rising prevalence of diverticulosis in young patients, although the exact level remains unknown. Other studies have suggested a rising prevalence of diverticulosis also, especially in societies where dietary habits have changed in type from traditional unprocessed to "Western" low-residue foods [27, 28]. However, the exact prevalence in younger patients in the United States is not yet known.
Conclusions
The results of this study suggest an increasing frequency of acute
diverticulitis in younger and obese patients in the urban U.S. population.
Supportive findings have been noted in a recently published study on a similar
patient population that found 72% of patients presenting with acute
diverticulitis were less than 50 years old
[29]. Severe disease requiring
hospital admission, surgery, percutaneous drainage, or both surgery and
percutaneous drainage is frequent in both younger and older age groups.
Because diverticulitis remains widely considered as rare in young patients, it
is important that the changing demographic trends in acute cases are
recognized. Traditionally, acute diverticulitis has not been considered in the
differential diagnosis of abdominal pain in young patients, so it is important
that radiologists understand the changing nature of this common disease.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  D. O. Jacobs Diverticulitis N. Engl. J. Med., November 15, 2007; 357(20): 2057 - 2066. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
) sagittal abdominal diameter and
standard error of patients by age group.