Preventing Unnecessary Appendectomies
Reported January 26, 2010
OAK BROOK, Ill. (Ivanhoe Newswire) — Preoperative computed tomography (CT) may help reduce unnecessary surgeries in women of reproductive age with suspected acute appendicitis.
“We found that rising utilization of preoperative CT over the past decade, along with advances in CT technology, coincided with a significant decrease in negative appendectomies among women 45 years and younger,” co-author Courtney A. Coursey, M.D., a radiologist at Emory University in Atlanta, Ga., was quoted as saying.
Acute appendicitis is inflammation of the appendix, a fingerlike organ attached to the large intestine in the lower right area of the abdomen. An inflamed appendix can perforate, resulting in a life-threatening infection.
While surgical removal of the appendix is the common treatment for acute appendicitis, diagnosis is not always clear clinically. Prior to the advent of CT, in inconclusive cases, physicians would often remove the appendix as a precaution. Historically, this resulted in a high rate of unnecessary appendectomies, with rates as high as 40 percent in women.
Negative appendectomy rates are generally higher in women due to gynecologic pathology that can confound appendicitis diagnosis. For instance, symptomatic ovarian cysts can cause lower abdominal pain similar to that of appendicitis.
CT now has the potential to reduce the negative appendectomy rate. An acutely inflamed appendix appears thick-walled on CT, and adjacent inflammatory changes are often visible. If the appendix is perforated, fluid next to the appendix can be visible on CT.
To determine the impact of CT on negative appendectomy rates, Dr. Coursey and colleagues reviewed a surgical database of 925 patients who underwent urgent appendectomy at Duke University Medical Center between January 1998 and September 2007. Over the 10-year period, the percentage of patients who had preoperative CT increased from 18.5 percent in 1998 to 93.2 percent in 2007.
The increased use of CT corresponded with a lower negative appendectomy rate for women age 45 years or younger. The negative appendectomy rate among those women dropped from 42.9 percent in 1998 to 7.1 percent in 2007. The shift from single-detector CT to multi-detector CT and other advances in CT technology also correlated with a reduction in false-positive diagnoses.
“CT is a very helpful test for women 45 years and younger based on the overall trends we observed during the 10-year period,” Dr. Coursey said.
Increased use of preoperative CT at Duke did not coincide with a lower negative appendectomy rate in men, regardless of age, or in women older than 45 years. Dr. Coursey suggested that the lack of a decline might be attributable to a very low negative appendectomy rate in those groups in the first place.
“Although it’s a terrific test, CT and our interpretation of CT images are not 100 percent perfect,” said Dr. Coursey. “Therefore, it may be difficult to improve significantly upon diagnosis in groups with an already low negative appendectomy rate.”
SOURCE: Radiology, February, 2010