Article, Surgery

Effect of time delays for appendectomy as observed on computed tomography in patients with noncomplicated appendicitis

a b s t r a c t

Objectives: Delaying appendectomy is a controversial issue. This study aimed at identifying the effect of time delays in surgery, especially for patients with noncomplicated appendicitis on computed tomography (CT).

Methods: Postappendectomy patients were analyzed from October 2013 to August 2014. Among the patients, data of those with findings of noncomplicated appendicitis on CT were gathered and the following time param- eters were reviewed: CT examination time and appendectomy time. Other basic information and postoperative complications were checked. Patients were divided into a noncomplicated appendicitis group and a complicated appendicitis group. Perforated appendicitis and periappendiceal abscesses were regarded as complicated appendicitis. All other appendicitis from simple, focal to suppurative, and gangrenous appendicitis were regarded as noncomplicated appendicitis.

Results: In total, 397 patients were enrolled. The mean age was 33.2 years and the number of male/female patients was 216:181, respectively. The mean times from CT to operation were 5.9 vs 6.3 hours for both the non- complicated and complicated appendicitis groups (P = .758). The time from CT to operation showed no statisti- cal relation to occurrences of complicated appendicitis, or postoperative complications such as ileuses, wound complications, and length of hospital stay.

Conclusions: The time from CT to operation has no effect on the results of appendicitis. Further study in large- scaled, multicenter setting might yield more reliable results.

(C) 2015


Appendicitis has been regarded as a condition requiring emergency surgery [1]. After luminal obstruction, the inflamed appendix may be perforated and the condition may progress to peritonitis or abscess without immediate surgery. Therefore, an appendectomy has to be performed urgently. There are several studies that support prompt appendectomy [2-5], whereas there are other studies suggesting that delayed appendectomy is acceptable and is not associated with a higher rate of complications [6-10].

Therefore, the ideal timing of appendectomy is still a controversial issue. This study aimed to identify the effects of time delays for appen- dectomy by analyzing patients with noncomplicated appendicitis (NA) on computed tomography (CT).

? The authors have nothing to disclose. No financial or other type of support was received.

?? This paper has not been presented previously.

* Corresponding author at: Department of Surgery, Division of Colorectal Surgery, Seoul St Mary’s Hospital, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul 137-701, Korea. Tel.: +82 2 2258 6100; fax: +82 2 595 2822.

E-mail addresses: [email protected] (M. Kim), [email protected] (S.-T. Oh).


A retrospective study was designed by reviewing medical records. The institutional review board approved the study and waived informed consent. Patients undergoing appendectomy between October 2013 and August 2014 who had a result of pathologically confirmed appendicitis were analyzed and their CT results were checked. A thickened appendix with a diameter larger than 6 mm, wall enhance- ment, or periappendiceal fat infiltration were regarded as signs of ap- pendicitis. Patients without these signs were excluded. Presence of periappendiceal bowel thickening and fat infiltration were regarded as signs of peritonitis. Patients with complicated appendicitis (CA) such as perforated appendicitis, peritonitis, or periappendiceal abscess for- mations at CT were excluded. Patients with other combined conditions such as diverticulitis, intussusception, Pelvic inflammatory disease, or tuboovarian abscess were excluded. Enrolled patients’ medical records were reviewed to check the following factors: sex, age, initial white blood cell count , body temperature, time of CT, time of appen- dectomy, surgical findings, postoperative complications, and length of hospital stay. The results of appendicitis were divided into either NA or CA. Simple, focal, or suppurative cases of appendicitis were regarded as NA, and perforated appendicitis, peritonitis, or periappendiceal abscesses were regarded as CA.

0735-6757/(C) 2015

168 M. Kim, S.-T. Oh / American Journal of Emergency Medicine 34 (2016) 167169

According to the time from CT to operation (tCT-OP), patients were divided into 2 groups. Patients with tCT-OP less than 6 hours were regarded as the prompt appendectomy group and patients with tCT-OP from 6 to 24 hours were regarded as the late appendectomy group. The operative outcome, primarily based on the results of appendicitis, was analyzed by tCT-OP. The postoperative complications after ileus, wound complication, and length of hospitalization stay were also analyzed.

For qualitative analysis, ?2 and Fisher exact tests were used, and for quantitative analysis, independent t tests were used. A P value less than

.05 was considered statistically significant. SPSS v17.0 (Chicago, IL) was used for all statistical analyses.


Table 2

Analysis of operative outcomes and tCT-OP

Prompt appendectomy (tCT-OP b 6 h)

Result of appendicitis NA

232 (84.1%)

94 (81.0%)



Postoperative ileus

44 (15.9%)

22 (19.0%)


274 (99.3%)

114 (98.3%)



Wound complication No

2 (0.7%)

251 (90.9%)

2 (1.7%)

101 (87.1%)



25 (9.1%)

15 (12.9%)

Length of hospital stay (d)

2.6 +- 1.1

2.6 +- 1.1


Late appendectomy P

(tCT-OP 6-24 h)

A total of 630 consecutive patients underwent appendectomies during the period, and there were 397 patients with NA results at CT. The overall mean age was 33.2 years. Male patients constituted 54.4% (n = 216) of total patients. Patients with CA accounted for 16.9% (n = 67) of enrolled patients. The mean tCT-OP was 6.0 hours.

Patients’ general characteristics are shown in Table 1. For preopera- tive findings, both NA and CA patients showed a similar age and sex dis- tribution. They also had similar initial WBC and body temperatures. There was no statistical difference for tCT-OP in either group (5.9 hours vs 6.3 hours, P = .758). For postoperative findings, patients with CA showed a tendency for more postoperative ileuses and longer lengths of hospital stay.

Operative outcomes were analyzed according to tCT-OP (Table 2). There was no statistical difference in either prompt appendectomy group or late appendectomy group results of appendicitis (P = .465). Postoperative complications and length of hospital stay were also statis- tically similar in both groups.


The present study was designed to evaluate the effect of time after CT on the results of appendicitis. Many studies have analyzed the time from presentation to appendectomy to evaluate whether delayed appendectomy produce worse outcomes [3-11]. These types of study assumed that the initial patients who presented at emergency depart- ment had similar NA. However, there exist patients with CA at the initial presentation, and without identifying these patients, the results might have been changed. In this respect, the present study used a unique de- sign. By undertaking a preliminary analysis, 103 patients with findings of CA at CT were excluded and only patients with NA at CT were further analyzed. One study did analyze time from imaging to operation [12]. However, there was no exclusion process according to the results of CT. In this study, patients were standardized by CT results. Moreover, initial WBC and body temperature were also similar in both groups.

Table 1

Characteristics of patients with NA and CA


Age (y) Sex

32.6 +- 17.4

36.1 +- 22.2



175 (53.0%)

41 (61.2%)



155 (47.0%)

26 (38.8%)


12.8 +- 4.2

14.0 +- 4.3


Body temperature

36.6 +- 0.5

36.6 +- 0.6


tCT-OP (hour)

5.9 +- 9.5

6.3 +- 5.7


Postoperative ileus


329 (99.7%)

64 (95.5%)



1 (0.3%)

3 (4.5%)

Wound complication


295 (89.4%)

61 (91.0%)



35 (10.6%)

6 (9.0%)

Length of hospital stay (d)

2.3 +- 0.9

3.7 +- 1.5


Therefore, the effects of time could be analyzed more rigorously from standardized patients.

Many studies have predicted the results of appendicitis by analyzing initial examinations. Computed tomography is one of the most common examinations to check patients suspected of having appendicitis. Its fea- sibility has been proven by many studies [13-15], although this modal- ity is associated with the risk of malignancy via radiation exposure and is more expensive [16,17]. It was used as a regular examination tool in our institution because of its superiority for diagnosis [18]. Ultrasonog- raphy (US) is another imaging tool for appendicitis. However, US has been known to show different sensitivities and specificities according to the sonographer’s skill and the location of the appendix. Therefore, US has limitations and has been used in limited situations.

A similar study demonstrated that the outcome of appendicitis is un- affected by the timing of the appendectomy [11]. This study showed a mean of 7.1 hours to surgical intervention. In another study, appendec- tomy was delayed to after 24 or 48 hours; this increased the rate of com- plications [3,5]. Similarly, in this study, the mean tCT-OP was about 6 hours, and the overall outcome showed that there were no correla- tions between time delay and the appendicitis outcome. Five patients also had a tCT-OP greater than 24 hours, and among these patients, there was one CA case (20%). Although the number of cases was too few to be confirmatory, it was higher than the overall incidence of CA (16.9%). Another large-scale, multicenter study that included patients with longer hospital delays of more than 24 or 48 hours might yield more rigorous and generalized outcomes.


It can be concluded that the time after CT showed no effect on the re- sults of appendicitis; tCT-OP showed no statistical difference regarding the results of appendicitis, postoperative complications, or length of hospital stay. For patients with NA at CT, appendectomy could be delayed 6 to 24 hours without considerable complications.


Both authors provided a significant contribution to this study. M.K. is the first author and contributed to the data collection, statistical analysis, and in writing the manuscript. S.O. is the corresponding author of this study and contributed to study design, interpretation, writing the manuscript, and critical revision.


The authors have nothing to disclose. No financial or other type of support was received.

M. Kim, S.-T. Oh / American Journal of Emergency Medicine 34 (2016) 167169 169


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