January 11, 2012 — The long-term risks for recurrent acute diverticulitis are limited after colectomy, but medically treated patients fare almost as well, researchers report in an article published online November 21, 2011, and in the February print issue of the British Journal of Surgery.
"These data do not support a general policy of prophylactic colectomy, which should be advised depending on the individual patient," write G.A. Binda, MD, from the Department of General Surgery, Galliera Hospital, Genoa, Italy, and colleagues.
Although diverticulosis is common in western countries, only about a quarter of patients experience acute diverticulitis. About a third of these patients have a recurrence, and about 10% need emergency surgery.
However, little is known about the natural history of the disease. Previous studies have been retrospective, or recruited only small numbers of patients, and sigmoid colectomy remains controversial, both as an elective and as an emergency procedure.
Some guidelines issued in the late 1990s recommended elective colectomy after a second episode of acute diverticulitis, but in 2006, the American Society of Colon and Rectal Surgeons suggested a more cautious approach.
To help provide guidance, in 1997 the Italian Group on Complicated Diverticulosis (GISDIC) began collecting detailed data on 743 patients admitted for left-sided acute diverticulitis at 17 surgical centers. Information on 407 patients admitted in 1996 and 1997 was gathered retrospectively and was combined with prospective records on 336 patients who were recruited in 1998 and 1999.
The researchers included in their study all consecutive patients with left-sided acute diverticulitis diagnosed clinically by the presence of abdominal pain, associated with leukocytosis (more than 11 × 109 cells/L) and/or fever exceeding 38°C, and confirmed by imaging (computed tomography [CT], ultrasonography, or water-soluble contrast enema), either alone or in combination with operative findings.
The authors excluded patients with inflammatory bowel disease, irritable bowel syndrome, colorectal cancer, or diseases precluding adequate follow-up, and they defined recurrence as a new episode of acute diverticulitis requiring hospital admission at least 2 months after complete resolution of the episode that originally led to inclusion in the study.
Clinicians at these centers administered medical treatment initially to 501 patients (67.4%). The patients had a median hospital stay of 9.1 days (interquartile range, 6 - 11 days). The surgeons performed CT- or ultrasonography-guided percutaneous drainage in 6 patients with pelvic abscess, of whom 5 underwent a surgical procedure during the same hospital admission. One 79-year-old woman died 7 days after admission for sepsis.
The surgeons operated on 32.6% of the patients, with a greater number of acute episodes the only variable associated with an increased probability of surgery.
The surgeons created a stoma in 66 (27.3%) patients, performed an end colostomy in 56 patients, and performed a resection with the anastomosis covered by a stoma in 10 patients. They performed emergency sigmoid resection and primary anastomosis without a covering stoma in the remaining patients. Eleven of the surgery patients died in the hospital.
Follow-up data were available for 474 patients. The mean actuarial follow-up was 10.7 years (95% confidence interval [CI], 10.4 - 11.0 years).
The researchers found a 21.9% prevalence of persistent chronic symptoms among the medically treated patients compared with a 16.2% prevalence among the surgically treated patients, which is a statistically significant difference (P = .047).
They also found that 17.2% of the medically treated group had 1 or more hospital admission for recurrent acute diverticulitis compared with 5.8% of the surgically treated group (P < .001). Likewise, the medically treated patients were almost 4 times more likely to be admitted for a recurrent episode of the disease (crude odds ratio, 3.76; 95% CI, 1.79 - 7.89; P < .001).
During 12 years of follow-up, 8.3% of patients in the medically treated group had subsequent emergency surgery compared with 1.9% in the surgically treated group (P = .008).
The researchers found no association between the risk for emergency surgery and sex, age at entry, and number of previous acute episodes. They also found no difference in the need for emergency surgery among patients entered either retrospectively or prospectively.
Limitations of the study include lack of distinction of treatment modality based on severity of disease, missing discharge data for roughly one third of the participants, and analysis of only those hospitalized for diverticulitis. In addition, the high operative rate reflects that even many at low risk for recurrence underwent surgery.
From the findings, the authors conclude that "[t]he natural history of conservatively treated [acute diverticulitis] seemed quite benign." Although patients in the medically treated group were more likely to experience chronic symptoms than the surgically treated patients, the difference was less than 6%, they point out.
Likewise, they write, the rate of recurrent acute diverticulitis was low even among the medically treated patients. Although the risk was higher among young patients, the study failed to show a time interval in which the recurrences were most likely to occur.
The researchers also found that a long history of diverticulitis or an increasing number of acute episodes were not necessarily associated with a higher risk for serious complications from surgery.
The authors have disclosed no relevant financial relationships.
Br J Surg. 2012;99:276-285. Abstract
