BOSTON – Though progress is being made in reducing surgery for diverticulitis, one in three elective colectomies failed to meet current indications in a prospective study.
Among 1,102 patients in Washington state with an episode-based indication for elective surgery, the proportion with three or more prior episodes of diverticulitis increased from 42% in 2010 to 58% in 2012 (P = .007), while the proportion failing to meet either complication- or episode-based indications decreased from 41.3% to 29.6% (P = .002).
"Still, there remains a significant and persistent portion of cases being done in Washington that do not meet established guidelines," Dr. Vlad V. Simianu said at the annual meeting of the American Surgical Association.
The study involved 2,031 patients having elective resection for diverticulitis in 2010-2012 in 49 hospitals in Washington state’s voluntary Surgical Care and Outcomes Assessment Program (SCOAP), which captures about 80% of the surgical volume in the state. Their mean age was 58.8 years, 24% were younger than 50 years, and most were healthy, with only 27% having a Charlson Comorbidity Index score of 1 or more.
Washington has seen a dramatic threefold increase in elective colectomy for diverticulitis over the last 13 years, despite evolving recommendations, observed Dr. Simianu, a general surgery resident and research fellow at the University of Washington, Seattle. The 2006 American Society of Colon and Rectal Surgeons (ASCRS) guidelines, which were used for the study end points, said elective surgery can be safely delayed until three or more acute episodes of uncomplicated diverticulitis. The ASCRS just updated its guidelines again (Dis. Colon Rectum 2014;57:284-94) and now strongly recommend that the decision to proceed to elective colectomy after recovery from uncomplicated acute diverticulitis "be individualized."
Among all 2,031 patients in the study, a clinical indication for surgery was present in 23.3% (chronic fistula 10.5%, stricture 5.4%, bleeding 2.4%, and other 5%), while 55% of the 1,102 patients with an episode-based indication had three or more episodes.
In 2010, 22% of all patients had at least three prior episodes, 17% had chronic complications, and 23% had neither. This compares with 37.7%, 18%.6%, and 16.7% in 2012.
Possible explanations for the rise in guideline-concordant cases are that surgeons are documenting their indications more carefully or are delaying more operations until three or more acute episodes, Dr. Simianu said. Indeed, there was a significant decrease in the number of cases with missing indications in the clinical record over the study period (38% vs. 27%; P = .007).
The persistence of cases not meeting indications could be because the adoption of laparoscopy has lowered the threshold for surgeons to offer colectomy, similar to what has happened with laparoscopic cholecystectomy, he said. A laparoscopic operation was performed in 60% of the patients.
Other possible explanations are that the guidelines don’t capture all relevant indications, like persistent symptoms or pain, or that evolving evidence and guidelines are forcing some surgeons to wait before they change their practice, Dr. Simianu said.
"Nonetheless, we view this as an educational opportunity in our state to give feedback to surgeons in our network," he said.
Notably, the rate of elective and emergency resections per year did not increase significantly over the study period at 28 high-volume hospitals, performing at least 10 colectomies yearly. Data, however, were incomplete or missing, in 30.4% of cases.
Discussant Dr. Conor Delaney, chief of colorectal surgery at University Hospitals Case Medical Center, Cleveland, said it was good to see that the percentage of cases performed for three or more episodes rose across all age groups in the final year of the study, suggesting that the SCOAP intervention is likely working.
"It is still shocking to see 30 or 40% of cases being performed for fewer than three attacks," he said, adding that the 30% of patients who had surgery without appropriate indications "may really be, very much a best-case scenario."
He also asked whether the investigators could identify hospitals inside and outside SCOAP that were less likely to follow guidelines and how they dealt with patients who may have had appropriate single-attack surgery because of nonresolution of symptoms or inadequate drainage.
Dr. Simianu said it wasn’t possible to determine indications for hospitals outside the SCOAP network, but that participating hospitals followed a normal distribution. High-volume hospitals were "sort of middle of the road," while four or five low-volume hospitals were outliers and never or always met indications.
In response to the second query, he said their clinical indications included an "other" category that captured appropriate first-attack patients and that about 1% of surgery was performed for an abscess.