Is it safe to delay appendectomy in adults with acute appendicitis?

Abstract

Objective: To examine whether delayed surgical intervention in adult patients with acute appendicitis is safe by correlating the interval from onset of symptoms to operation (total interval) with the degree of pathology and incidence of postoperative complications.

Summary background data: Prompt appendectomy has long been the standard of care for acute appendicitis because of the risk of progression to advanced pathology. This time-honored practice has been recently challenged by studies in pediatric patients, which suggested that acute appendicitis can be managed in an elective manner once antibiotic therapy is initiated. No such data are available in adult patients with acute appendicitis.

Methods: A retrospective review of 1081 patients who underwent an appendectomy for acute appendicitis between 1998 and 2004 was conducted. The following parameters were monitored and correlated: demographics, time from onset of symptoms to arrival at the emergency room (patient interval) and from arrival to the emergency room to the operating room (hospital interval), physical, computed tomography (CT scan) and pathologic findings, complications, length of stay, and length of antibiotic treatment. Pathologic state was graded 1 (G1) for acute appendicitis, 2 (G2) for gangrenous acute appendicitis, 3 (G3) for perforation or phlegmon, and 4 (G4) for a periappendicular abscess.

Results: The risk of advanced pathology, defined as a higher pathology grade, increased with the total interval. When this interval was <12 hours, the risk of developing G1, G2, G3, and G4, was 94%, 0%, 3%, and 3%, respectively. These values changed to 60%, 7%, 27%, and 6%, respectively, when the total interval was 48 to 71 hours and to 54%, 7%, 26%, and 13% for longer than 71 hours. The odds for progressive pathology was 13 times higher for the total interval >71 hours group compared with total interval<12 hours (95% confidence interval = 4.7-37.1). Although both prolonged patient and hospital intervals were associated with advanced pathology, prehospital delays were more profoundly related to worsening pathology compared with in-hospital delays (P < 0.001). Advanced pathology was associated with tenderness to palpation beyond the right lower quadrant (P < 0.001), guarding (P < 0.001), rebound (P < 0.001), and CT scan findings of peritoneal fluid (P = 0.01), fecalith (P = 0.01), dilation of the appendix (P < 0.001), and perforation (P < 0.001). Increased length of hospital stay (P < 0.001) and antibiotic treatment (P < 0.001) as well as postoperative complications (P < 0.001) also correlated with progressive pathology.

Conclusion: In adult patients with acute appendicitis, the risk of developing advanced pathology and postoperative complications increases with time; therefore, delayed appendectomy is unsafe. As delays in seeking medical help are difficult to control, prompt appendectomy is mandatory. Because these conclusions are derived from retrospective data, a prospective study is required to confirm their validity.

FIGURE 1. Relationship between advanced pathology and interval from onset of symptoms to surgery (total interval). A, Distribution of pathology grades per total intervals. B, Total interval and pathology grade proportions were compared using Mantel-Haenszel χ² test for trend. Odds ratios (OR) compare the likelihood of advanced pathology for a given total interval to those with a total interval less than 12 hours. Bars represent 95% confidence intervals (CI) and the dashed line indicates OR = 1 (ie, if 1 is contained within the 95% CI, then the odds for advanced pathology for this total interval are not significantly different than the odds for the <12 hours group). G1–G4, pathology grades as defined in Patients and Methods.

FIGURE 2. Relationship between patient to hospital interval ratio and degree of pathology. A, Relationship between patient interval and pathology grade. B, Relationship between hospital interval and pathology grade. C, Relationship between patient and hospital interval ratio and degree of pathology. Please note that increased patient and hospital intervals as well as patient and hospital interval ratio were associated with advanced pathology (P for trend from linear regression <0.01). This indicates that patient delay more significantly contributes to progressive pathology. Data are expressed as medians with bars representing 25th and 75th percentile. G1–G4, pathology grades as defined in Patients and Methods.