Research Article
Does Time Till Surgery Affect the Outcome of Uncomplicated Acute Appendecitis: A Retrospective Cohort Study
Zvi H Perry1,2, Uri Netz1, Solly Mizrahi1, Shahar Atias1, Leonid Lantsberg1 and Boris Kirshtein1*
1Department of Surgery, Soroka University Medical Center, Israel
2Department of Epidemiology and Health Services Evaluation, Ben-Gurion University of the Negev, Israel
*Corresponding author: Boris Kirshtein, Department of Surgery, Soroka University Medical Center, POB 151, Beer-Sheva 84101, Israel
Published: 24 Apr, 2017
Cite this article as: Perry ZH, Netz U, Mizrahi S, Atias S,
Lantsberg L, Kirshtein B. Does Time
Till Surgery Affect the Outcome of
Uncomplicated Acute Appendecitis: A
Retrospective Cohort Study. Clin Surg.
2017; 2: 1428.
Abstract
Background: Laparoscopic appendectomy is the most frequent on-call surgery done as an
emergency. We evaluated the outcome of extending the period from admission till surgery for uncomplicated
acute appendicitis in adults.
Methods: A retrospective study of all patients who underwent laparoscopic appendectomy in our
department between 2000 and 2010 was conducted. The patients were operated upon by novice
surgeons, chief residents, and senior surgeons. Pre-operative variables were compared, as well as
surgical outcomes and complications.
Results: 887 patients were enrolled. Of these, 749 were uncomplicated acute appendicitis patients.
An analysis of the 749 uncomplicated cases of acute appendicitis revealed no association between
illness duration and time till surgery upon intra- and post-op complications, as seen in uni-variate
analysis. When multi-variate analysis was conducted, the same results were attained. Gender and
surgical duration were risk factors for further complications. By Adding the 77 patients who suffered
from complicated appendicitis did not change the statistical outcome.
Conclusion: Delayed appendectomy for uncomplicated acute appendicitis in adults does not
adversely affect 30-day outcomes.
Keywords: Acute appendicitis; Laparoscopy; Timing; Delay in surgery; Complications
Introduction
Appendectomy is the most frequent procedure performed as an emergency procedure in general surgery [1]. The issue of timing for the appendectomy has been debated [2,3]. Green et al. showed no conclusive evidence to guide surgeons when to operate on un-complicated acute appendicitis [4,5]. Herein in a retrospective study we evaluated the effect of timing upon the outcome of uncomplicated acute appendicitis.
Materials and Methods
Adult patients with suspected acute appendicitis who underwent a laparoscopic appendectomy
or a diagnostic laparoscopy were enrolled. The medical records of patients who underwent a
laparoscopic appendectomy for suspected acute appendicitis between 2000 and 2010 in Surgery A
at Soroka University Medical Center, Beer Sheva, Israel, were reviewed retrospectively.
Patients who underwent incidental or elective appendectomy were excluded, as well as patients
who were diagnosed as complicated appendicitis (frank peritonitis, sparkling fever, WBC>20000).
810 eligible subjects were admitted with suspected uncomplicated appendicitis. In 749 patients
out of 810 we able to conduct a multi-variate analysis, due to missing variables.
After obtaining approval of our institutional review board, a retrospective cohort study using
the records of all our patients who underwent laparoscopic appendectomy, with the principal
exposure being time to operation. Regression models yielded probabilities of outcomes adjusted for
patient and operative risk factors.
The retrieved data included patient demographics, preoperative laboratory and imaging data, intra-operative findings and pathology results, operator experience,
operative time, intra- and post-operative complications, surgery
outcome, and length of postoperative hospital stay. Time to surgery
was defined from admission to the emergency room till initiation of
surgical procedure.
We measured thirty-day overall morbidity and serious morbidity/
mortality events.
We evaluated the outcomes and complication rate in patients
who underwent surgery from onset of abdominal symptoms and
those from hospital admission.
A standard laparoscopic appendectomy via three ports had been
carried out in all cases. A diagnosis of acute appendicitis [6] was
based only on the pathological findings of the appendix. Complicated
appendicitis was defined by the intra-operative finding of gangrene
or perforation, as well as the presence of an intra-abdominal abscess.
Patients with a histologically normal appendix or patients with
intra-operative findings of other intra-abdominal pathologies were
classified as a "negative" appendectomy.
Postoperative complications were defined as SSI (surgical site
infection) when post-operative fever, intra-abdominal abscess or
phlegmon, wound infection, urinary tract infections, or pneumonia
were present after surgery.
Statistical analysis and sample size calculation
The data were coded and stored using a Microsoft Office Excel
program, and analyzed with SPSS 18.0 (SPSS, Chicago, IL). Data are
reported as mean±SD.
The comparison of groups was conducted using Pearson
Chi square for categorical variables and Fisher's exact tests for
dichotomous variables when applicable. Comparison of quantitative
variables was done using parametric (e.g., t-test) and a-parametric
(e.g., Mann-Whitney test) tests.
Differences were considered statistically significant at p< 0.05.
After univariate analysis we conducted a multivariate analysis
including regression models. Sample size was computed using the
WINPEPI computer program (http://www.brixtonhealth.com/pepi4
windows.html), using the COMPARE function (simple proportions
study) with the following assumptions: Odds Ratio of 3 or less
was considered negligible, power was set at 80%, and α=0.05. The
proportion assumed as baseline was 6%, and a ratio of 1:1 was defined.
With these assumptions, the minimal sample size needed is 151 in
each group or 302 in total. After continuity correction, the minimal
number needed was set at 342. The number of patients surveyed was
in fact 887.
Results
In the study population of 887 patients, 293 were males (33.0%).
Median ASA was 1, and average age at operation was 37.6±16.2. Of
887 patients enrolled, 555 (62.6%) were admitted with the diagnosis
of acute appendicitis. Sixteen cases (1.8%) were converted to an open
procedure. One hundred seven patients (12.1%) had suffered from
surgical complication (intra-operative, early or late post-procedural
complications). Ninety-four patients (10.5%) had been defined
during surgery as complicated appendicitis (gangrene, perforation or
abscess).
Compared patients who suffered from complications during or
after surgery.
The main difference between patients who suffered from
complications differed in their leukocyte count and temperature only,
and without clinical relevance.
The logistic models to discern whether delay in surgery is a risk
factor for complications. The length of pre-hospital and in-hospital
illness was not significant risk factors for complications.
Being a female seemed to have a protective statistical effect against
complications, whereas surgical duration was found to be a risk factor
for complication.
749 patients with uncomplicated appendicitis were re-analyzed
for the effect of time till surgery upon post-op complications. We
found no significant difference.
When trying to find an optimal duration between admissions till
surgery, no significant cut off period was detected.
Comments
The aim was to see whether a delay in performance of an
appendectomy for suspected acute appendicitis is a risk factor for
post-op complications. Our results have shown that a delay in surgery
had no deleterious effect on patients' health, complication rate, or
long-term morbidity or mortality.
In contrast to patients who require urgent surgery (i.e. peritonitis,
sparkling fever or elevated white count), we found uncomplicated
appendicitis patients who have equivocal findings and the issue
of surgery is not clear cut, the delay in surgery does not inflict any
grave consequences. We have seen that hospital duration and the
pre-hospital duration had no significant effect on intra or post-op
complications, whereas the length of surgery was a significant risk
factor (OR=1.026, p=0.012), as shown in previous studies [3-5,7,8].
Mounting evidence has shown that delayed appendectomy
for acute un-complicated appendicitis had no real implications on
morbidity and mortality, some institutions in the world do not subject
the uncomplicated appendicitis patients for surgery any more. Thus,
Eko et al. [3] have concluded that the timing of surgery had no effect
on complications such as perforation.
Giraudo et al. [9,10] have shown that performing appendectomy as
long as 24 h from presentation does not increase the length of hospital
stay or rate of complications and Gopte et al. [11] have concluded that
it is better to wait in cases with doubtful initial diagnosis of appendicitis
on admission in order to decrease negative appendectomy rates, and
that this policy has not increased complications rates. In view of all
these studies, we feel that our results stand on mounting scientific
evidence that delaying the performance of an appendectomy for a few
hours had no real implications on morbidity or mortality.
The delay of appendectomy for acute appendicitis in adults does
not appear to adversely affect 30-day outcomes.
As for the limitations of our study there are some points need to
be further evaluated, such as a larger sample size, as well as the need
for a multi-center study may solidify our conclusions.
To conclude, we suggest that a delay of appendectomy for
suspected acute appendicitis in adults does not appear to adversely
affect 30-day outcomes. As well as a delay-either in diagnosis or
surgical treatment thereafter-is acceptable as long as the patient is
under the proper surgical supervision.
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